Page 1 of 2 12 LastLast
Results 1 to 35 of 47

Thread: Very old pignose 7-100

Hybrid View

Previous Post Previous Post   Next Post Next Post
  1. #1
    Junior Member
    Join Date
    Aug 2008
    Posts
    10
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0

    Very old pignose 7-100



    Hello, please let me introduce myself, ( where have i heard that line before ).

    My name is Larry, nickname Larwood, and I'm here on this site not only to try and share info whenever i can about my hobby of building Valve/Tube Amps, but also to get help on the mysterious world of Stomp boxes, and my once Trusty go anywhere with me, Pig nose.

    Now as hard as i scour this wonderful,weird,web, I cannot find a schematic out there anywhere, can anyone help? The one way i would suggest if we cant find one, is for me to post a small drawing if its allowed, of the resistor that burned to a frazzle before my eyes as a techie tried to show me where to connect an adapter, instead of running it on batteries.
    Of course this part used to look like a resistor, but now resembled a small sample of my wives cooking, burnt, black as your hat and no way of ID'ing it.

    Now this all happened 12years or so ago,and the old old Pignose has been laying in the back of my workshop since then.If we could establish the age and place of manufacture which i believe to be L.A,
    with a Serial No of 28315
    and a Model No of 7-100,
    PCB No 104/032/041.

    I may get another chance to hear the wonderful tone of a piece of equipment trying it's best to operate as the six 1.5v batteries start to flag or sag or go flat, whatever, but that tone I've missed it.

    I can tell you that it's the largest resistor or whatever it is (Diode maybe?) on top of the PCB as soon as you take the black metal shield away.

    I do HOPE that this problem will soon be a thing of the past and Piggy will be singing away again,and then we can start talking stomp box lingo and the questions that arise from the cloneing and patent issues that always seem to rear their ugly heads if some person comes up with a cracking pedal and immediately gets jumped on.
    All that for next time eh.

    Appreciate your help in advance.

    Larwood.

    0 Not allowed! Not allowed!

  2. #2
    Lifetime Member Enzo's Avatar
    Join Date
    May 2006
    Location
    Lansing, Michigan, USA
    Posts
    31,785
    Thumbs Up/Down
    Received: 1,655/7
    Given: 0/0
    Rep Power
    54
    Hi, welcome to the forum.

    Did you contact Pignose and ask if they could provide the schematic?

    0 Not allowed! Not allowed!

  3. #3
    Senior Member
    Join Date
    Jun 2007
    Posts
    617
    Thumbs Up/Down
    Received: 22/0
    Given: 0/0
    Rep Power
    13
    Here's a schematic for some post 1986 models. I believe there have been several revisions of this amp so not all component values may apply. You need to do a little bit of detective work to find out how accurate this diagram actually is. For example, I heard rumors that newer Pignose 7-100's just have a IC-based power amp section and no longer use transformer coupling (I haven't opened up a new Pignose to verify this, though). That would mean the circuit would be entirely different. Anyway, let's hope this diagram helps.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	Pignose7-100.gif 
Views:	19589 
Size:	32.1 KB 
ID:	2907  

    0 Not allowed! Not allowed!

  4. #4
    New Member
    Join Date
    Jul 2012
    Posts
    1
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    I have one of the early 70's models, originally bought in about '76 or '77 for me as a present. I had once completely fried the board by applying a high power source, (young and inexperienced) I ordered a new board shortly thereafter from the company I think it was called Pignose international, could be wrong about that. I have had this board in there ever since, I used to carry this little pignose with me everywhere. It has worked very well for all of these years, when the original speaker cone broke I put in a speaker from radio shack which worked fairly well, I thought I would make a great improvement and install an actual Celestion speaker, five inch just like the original with about the same size magnet, looked like almost an exact match, although this speaker is 8 Ohm. It took me years to figure out just how to reconnect the original connection for an adaptor. I did get it to work, but I started noticing after great sound at first, the whole thing starts to fade out almost completely until it cannot be heard or just barely even at full volume. I once again took out the board, removed the metal cover around the transformers I immediately found the transistor on the left side extremely hot to the touch, once it cools down it sounds ok again. Is this caused only by a faulty transistor and can I replace it with another germanium transistor, I have built several fuzz boxes with varying success with transistors from a local large electronics store. Are these PNP NPN transistors, I didn't see anything in any of the previous post stating what type they are, the transistors are the same as was mentioned earlier in this post, Two B324's, one B175 and one B172, I would to get any help on this I love this little amp.

    0 Not allowed! Not allowed!

  5. #5
    Old Timer
    Join Date
    Jun 2007
    Posts
    5,096
    Thumbs Up/Down
    Received: 85/0
    Given: 54/0
    Rep Power
    19
    Quote Originally Posted by ClassicRocker View Post
    Is this caused only by a faulty transistor and can I replace it with another germanium transistor, I have built several fuzz boxes with varying success with transistors from a local large electronics store. Are these PNP NPN transistors, I didn't see anything in any of the previous post stating what type they are, the transistors are the same as was mentioned earlier in this post, Two B324's, one B175 and one B172, I would to get any help on this I love this little amp.
    I assume the transistor that gets hot is a B324? One of the outputs. It could just be a bad transistor or it could be a circuit problem. I'd replace the transistor as a first step. It is a germanium PNP, 2SB324.

    0 Not allowed! Not allowed!

  6. #6
    Member
    Join Date
    Jan 2008
    Posts
    67
    Thumbs Up/Down
    Received: 1/0
    Given: 0/0
    Rep Power
    12

    Pignose problems

    Hi, old thread, new problem. I have a 7-100 model that passes signal but there is a lot of crackling and other noises. I cleaned thevolume pot but still have the problem. Any insights as to possible causes, seems like a grounding noise. I have the original power supply and it does the same thing under battery power.

    0 Not allowed! Not allowed!

  7. #7
    Lifetime Member Enzo's Avatar
    Join Date
    May 2006
    Location
    Lansing, Michigan, USA
    Posts
    31,785
    Thumbs Up/Down
    Received: 1,655/7
    Given: 0/0
    Rep Power
    54
    Does the noise seem to relate to using the pot? Or did you just clean it for old times' sake? If the pot makes noise, it can be other things than needing cleaning. The pot can be worn out or have cracked solder, so motion triggers noise. Also, if a pot has DC voltage across it, it will be noisy when moved.

    Does tapping the amp make noises? That would be a loose connection somewhere. Don;t be shy, give it a solid swat on top.

    If it just sits there alone making pops and crackles and grumbling noises, my first suspect is a noisy transistor.

    0 Not allowed! Not allowed!
    Education is what you're left with after you have forgotten what you have learned.

  8. #8
    Member
    Join Date
    Jan 2008
    Posts
    67
    Thumbs Up/Down
    Received: 1/0
    Given: 0/0
    Rep Power
    12

    just sitting there

    Hi Enzo, just just sitting there its constantly crackling and popping. I do get a signal and can hear the guitar ok. The Pot simply makes it all louder. I reflowed all the solder joints, still there? How do i trouble shoot further please. Looks like its 2SB56 germanium Transistors.

    Best A

    Quote Originally Posted by Enzo View Post
    Does the noise seem to relate to using the pot? Or did you just clean it for old times' sake? If the pot makes noise, it can be other things than needing cleaning. The pot can be worn out or have cracked solder, so motion triggers noise. Also, if a pot has DC voltage across it, it will be noisy when moved.

    Does tapping the amp make noises? That would be a loose connection somewhere. Don;t be shy, give it a solid swat on top.

    If it just sits there alone making pops and crackles and grumbling noises, my first suspect is a noisy transistor.

    0 Not allowed! Not allowed!
    Last edited by angelodp; 08-18-2012 at 05:48 AM.

  9. #9
    Lifetime Member Enzo's Avatar
    Join Date
    May 2006
    Location
    Lansing, Michigan, USA
    Posts
    31,785
    Thumbs Up/Down
    Received: 1,655/7
    Given: 0/0
    Rep Power
    54
    Isolate the problem. Can you turn the volume control to zero and kill the noise?

    I'd use a scope or a signal tracer (google that) to follow the signal path through teh amp. It is only two transistors in the preamp, and a pair in the power amp.

    I'd try grounding the signal path. There is DC on the transistors so don;t ground it directly, but a large cap like a 0.1uf clipped to ground then touched to circuit points will serve to shunt off a lot of the signal. SO if grounding the base of the first transistor with a cap diminishes the noise, or muffles it, then we know the noise was coming in there, and if that has no effect, then the noise is later in the circuit. SO we do the ame thing at the base of the second transistor. Or at the collector of each. Step through the circuit this way to find at what point the noise enteres.

    Other techniques would be to hit parts with freeze spray to see if the thermal shock affects the noise. Or heat.

    0 Not allowed! Not allowed!
    Education is what you're left with after you have forgotten what you have learned.

  10. #10
    Member
    Join Date
    Jan 2008
    Posts
    67
    Thumbs Up/Down
    Received: 1/0
    Given: 0/0
    Rep Power
    12
    Ok great. Are replacement Transistors readily available? Which leg is the base of the transistor please. Tried it with a .22uf cap and it just made a loud buzz on the transistor legs?? No shunting of noise ( crackle pop ). BTW vol to zero kills noise.

    0 Not allowed! Not allowed!
    Last edited by angelodp; 08-18-2012 at 06:27 AM.

  11. #11
    Lifetime Member Enzo's Avatar
    Join Date
    May 2006
    Location
    Lansing, Michigan, USA
    Posts
    31,785
    Thumbs Up/Down
    Received: 1,655/7
    Given: 0/0
    Rep Power
    54
    All the 7-100 circuits I know have the volume control before the entire circuit. So if the thing kills the noise, it wouldn;t be coming from the circuitry. I'd make sure the input jack is snug and its contacts clean.

    How about this: turning the volume to zero kills the noise, OK, now plug a guitar into the input jack and turn the volume control on the guitar itself to zero, but leave the control on the amp up. Does THAT kill the noise? I am wwondering if the grounding contact on the empty jack is making noises.

    0 Not allowed! Not allowed!
    Education is what you're left with after you have forgotten what you have learned.

  12. #12
    Lifetime Member Enzo's Avatar
    Join Date
    May 2006
    Location
    Lansing, Michigan, USA
    Posts
    31,785
    Thumbs Up/Down
    Received: 1,655/7
    Given: 0/0
    Rep Power
    54
    Oh, yes, suitable transistors are certainly available. As to which leg is which, I have no idea what transistors you have in there.

    0 Not allowed! Not allowed!
    Education is what you're left with after you have forgotten what you have learned.

  13. #13
    Member
    Join Date
    Jan 2008
    Posts
    67
    Thumbs Up/Down
    Received: 1/0
    Given: 0/0
    Rep Power
    12

    still there

    ok here is a ne twist. With the guitar volume full up the amp volume pot seems to generate less noise at it reaches full rotation. So it progressively gets more scratchy as you turn the amp volume pot up and then at the very end of travel of the amp pot it dies back a bit but still scratchy??

    With the guitar volume all the way down and the amp volume up it still makes noise.

    Wait a minute..... Enzo I think I found the culprit. The # 3 leg of the amp vol pot ( that goes to the signal on the jack ) that tab was cracked.... so poor connection. I am cleaning up the pot and will re-insatll with fresh connections soon.

    Best A

    NOPE.... still very scratchy and I do think this pot is a gonner. Any idea where I can get a similar 39D PC65- 10KA made i n japan has the on/off

    Quote Originally Posted by Enzo View Post
    All the 7-100 circuits I know have the volume control before the entire circuit. So if the thing kills the noise, it wouldn;t be coming from the circuitry. I'd make sure the input jack is snug and its contacts clean.

    How about this: turning the volume to zero kills the noise, OK, now plug a guitar into the input jack and turn the volume control on the guitar itself to zero, but leave the control on the amp up. Does THAT kill the noise? I am wwondering if the grounding contact on the empty jack is making noises.

    0 Not allowed! Not allowed!
    Last edited by angelodp; 08-18-2012 at 07:30 PM.

  14. #14
    Member
    Join Date
    Jan 2008
    Posts
    67
    Thumbs Up/Down
    Received: 1/0
    Given: 0/0
    Rep Power
    12
    I took the pot out and went threw it carefully and its fine and working. I did realize ( thanks to Howard at Pignose ) that the transistors that are most at risk are in the little round heat sinks that are attached to the transformer cover and Enzo you were quite correct they are B324 ( SB324 ). I found a couple on ebay for $5 and waiting to throw them in and see. Howard indicates that these two T's are the most often seen part failure, albeit rare. Will report back soon and thanks for the help.

    0 Not allowed! Not allowed!

  15. #15
    Member
    Join Date
    Jan 2008
    Posts
    67
    Thumbs Up/Down
    Received: 1/0
    Given: 0/0
    Rep Power
    12
    Ok got it going again. It turns out that it was not the transistors in the heat sinks. I got two replacement 2sb32's and the problem persisted. I tried the coolant from an air can on the other two transistors and the 2SB54 diminished in noise when sprayed. I compared the specs for 2sb32 and 2sb54 and they were so close that I decide to pop in the sb32 into that slot that was helped by the coolant..... presto.... pignose back to its old self. The upside down air can trick seems to be quite useful in zeroing in on the bad component.

    Thanks

    0 Not allowed! Not allowed!

  16. #16
    Junior Member
    Join Date
    Aug 2008
    Posts
    10
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Quote Originally Posted by Enzo View Post
    Hi, welcome to the forum.

    Did you contact Pignose and ask if they could provide the schematic?
    Hi Enzo,

    I just took it for granted that they ( pig nose ) would not release the schematic into the public domain, this is the info i had picked up from searches on other AMP & EFFECT SITES, while searching for info to repair my JEN Mr Crybaby, that still needs to be done as well. Pignose have schematics posted for their foot pedal effect "The Detonator" and i believe the G40 Amplifier, but the general concensus was no 7-100 schematic,s existed.
    But i suppose i,ll have nothing to lose by trying them direct. I do have a schematic to look at that has been posted by a member, and see if that tallies up with other components on the board, if all works well i'll save that schematic for future reference for myself and other members.
    Thanks.

    Larwood.

    0 Not allowed! Not allowed!

  17. #17
    Member Emeritus Forever Rob Mercure's Avatar
    Join Date
    May 2006
    Location
    Wise, Virginia
    Posts
    624
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    14
    Wow, just looked at the schemo that Teemuk provided and the only thing that comes to mind is "transistor radio." The amp is almost the exact audio section from the first "6 transistor" Japanese radios of the late 1950s - early 1960s.

    Rob

    0 Not allowed! Not allowed!

  18. #18
    Junior Member
    Join Date
    Aug 2008
    Posts
    10
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Quote Originally Posted by Rob Mercure View Post
    Wow, just looked at the schemo that Teemuk provided and the only thing that comes to mind is "transistor radio." The amp is almost the exact audio section from the first "6 transistor" Japanese radios of the late 1950s - early 1960s.

    Rob
    Hi Rob,
    Time to hold the hands up here i think, never been a tranny lover until late, actually when it was time to try to sort out the Cry Baby, I dont want to get into any for and against type of forum polls, but i must lay my cards on the table here, but i quite literally, sleep, eat & drink tubes/valves. So i am going to find myself on one of Leslie West's Sleigh Rides here, and i think i'm going to enjoy the curve. I will accept any help and or criticism,if anybody thinks i,m starting to run off track, I do have a nice 1963 BUSH Transistor in the workshop that usedto belong to my Father, so time to open her up and go to school i think.

    Larwood

    0 Not allowed! Not allowed!

  19. #19
    Old Timer
    Join Date
    Jun 2007
    Posts
    5,096
    Thumbs Up/Down
    Received: 85/0
    Given: 54/0
    Rep Power
    19
    The original ones I remember, used a pre-made circuit board that was also sold at places like Allied and Lafayette. They had a metal cover that also served as the heatsink for the output transistors.

    And as Teemuk's schematic shows, these were japanese 2SB germanium transistors. That leads me to believe that the schematic is in fact for pre 1984 versions. The ones I see now-a-days have silicon TO-220 outputs.

    I have not yet seen any IC versions, but I wouldn't be surprised if they have moved on to a LM386 version.

    0 Not allowed! Not allowed!

  20. #20
    Supporting Member Dave Curtis, dB AudioTech's Avatar
    Join Date
    Jun 2007
    Location
    USA
    Posts
    410
    Thumbs Up/Down
    Received: 7/0
    Given: 0/0
    Rep Power
    13
    Here's the one I have.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	Pignose model 7-100.gif 
Views:	39831 
Size:	44.8 KB 
ID:	2913  

    1 Not allowed! Not allowed!

  21. #21
    Junior Member
    Join Date
    Aug 2008
    Posts
    10
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Quote Originally Posted by Dave Curtis, dB AudioTech View Post
    Here's the one I have.
    Hi Dave,
    I thought it about time i pulled the Pignose off the shelf and remove the shield protecting the circuit, that done I've unclipped the transistors from off the power & output transformer shield to see if we can throw a bit more light on the date of the circuit board,

    They are :- B324(G)

    And the two on the board are :-B172(A) & B175(B)

    I also ran a search on the names that 52 Bill threw into the mix, my eyes have been well and truly opened, Lafayette closed down 1970, and the site
    www.childhoodradios.com really blew me away, especially the link to the Lafayette Radio Club.

    Hope this helps.

    Larwood

    0 Not allowed! Not allowed!

  22. #22
    Junior Member
    Join Date
    Aug 2008
    Posts
    10
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Just replying to my own post here, the transistor set up is exactly the same as Dave's schematic so i'll just start chasing it down to see if other values are the same on the board. Things, i feel are starting to look good.

    0 Not allowed! Not allowed!

  23. #23
    Lifetime Member Enzo's Avatar
    Join Date
    May 2006
    Location
    Lansing, Michigan, USA
    Posts
    31,785
    Thumbs Up/Down
    Received: 1,655/7
    Given: 0/0
    Rep Power
    54
    Asian transistor types have numbers that start with "2S", just as American types start with "2N." The asian transistor makers generally leave off the 2S as understood. Thus B324 is really 2SB324, and so on. If you look at Dave's schematic with that in mind, you will find your transistors are the same ones listed in that schematic.

    0 Not allowed! Not allowed!

  24. #24
    Junior Member
    Join Date
    Aug 2008
    Posts
    10
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Quote Originally Posted by Enzo View Post
    Asian transistor types have numbers that start with "2S", just as American types start with "2N." The asian transistor makers generally leave off the 2S as understood. Thus B324 is really 2SB324, and so on. If you look at Dave's schematic with that in mind, you will find your transistors are the same ones listed in that schematic.
    Hi Enzo,
    Thanks for the info regarding the 2S & 2N Prefix's, that is one for the note book in this late lesson in life about Solid State components.
    I had in fact just spotted my oversight just as my post hit the Ether, and as you can see, i sort of sent myself a post to show what can happen if you don't analyze a drawing before shooting off onto the stage in the proceedings. I also received an Email from Howard@ Pignose this morning, with the component list echoing Dave's Schematic.
    So it seems as between you all you have solved the date issue, Howard seems to think it's Post 86 by the schematic that was Emailed to me, i can only ask would you all tend to be in agreement with that?
    Now the only thing is to build up a component by component circuit board, and hopefully by process of elimination that burnt out resistor, will show itself. Then after we have installed anew one on the board, i will have to find out what was the real cause of the burn out, somehow i just cant see it being an adapter, even if the polarity had been reversed, with enough steam in it to burn out what appeared in size to be possibly a 2W resistor.
    But things are looking up and hopefully this Little Piggy should be singing before much longer.

    Larwood.

    0 Not allowed! Not allowed!

  25. #25
    Lifetime Member Enzo's Avatar
    Join Date
    May 2006
    Location
    Lansing, Michigan, USA
    Posts
    31,785
    Thumbs Up/Down
    Received: 1,655/7
    Given: 0/0
    Rep Power
    54
    Which part it is? What other parts does each end connect to?

    Then after we have installed anew one on the board, i will have to find out what was the real cause of the burn out, somehow i just cant see it being an adapter, even if the polarity had been reversed,
    Excuse me? I can think of no faster way to burn out parts on a little board than reverse polarity power. The transistors don't like it, nor do those electrolytic caps. And tantalum caps have almost no tolerance for it, if you have any in there.

    222ma from a 9v source makes 2 watts. Chances are your adaptor can handle at least that much.

    Educating my customers as to power adaptor selection and use is one of the most common lectures I serve up.

    0 Not allowed! Not allowed!

  26. #26
    Junior Member
    Join Date
    Aug 2008
    Posts
    10
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Enzo, we're going back some 12-15Yr's here and much of what i remember was my Pignose going up in smoke.

    Now this techie with the adapter just turned up at a jam we were having at a friends house, and the batteries in the amp were running low, also giving off that beautiful distortion as they do so. He takes out this adapter and set it for 9v, as for the rest of the specs, i haven't a clue , it was one of those modern at the time multi voltage, i think Ross adapter's, and plugged it in.

    Nothing happened at all, even left it connected as he swung the case open to pull the batteries, at the same time the amp just started to smoke, he pulled the plug , but alas to late.

    Now i don't know if you've ever seen the plate where you plug an adapter into on a Pig nose, but it's just a standard 3.5mm jack socket without ref to any form of polarity, in fact, all it does say is 9v-adapter.Also this guy roadied for a couple of bands that i knew of, so the last thing on my mind was to question what the **** had he just done. Needless to say that was the end of my jamming session, and the one good thing that came out of it ,I never let him within 10 meter's of my kit, and i ask him now all these years later, has he managed to kill any Pigs lately.

    Now as i said in one of my other posts, i am going to pull the circuit board and put all the specs, around the offending Resister down on a piece of paper and hopefully we should find the value that way.

    Now if what you have pointed out in your post is likely to have happened, i am going to have a seriously sick amp regarding the other parts on the board, and the outlook maybe to anticipate and get ready to replace all components on the board.

    Enzo i cant thank you enough in helping me to get my feet wet, so to speak in my speed course into solid state circuitry, and my ignorance of the power situation is unforgivable, but all these lessons learned now will provide well for the future. I have some specification figures from that factory schematic here and i,ll just type them below

    SOURCE = 9V dc
    OPEN LOOP = 15MV
    MAX CURRENT = 400MA
    INPUT IMPEDANCE = 50K

    As I've pointed out this is for a 7-100R, POST 1986

    0 Not allowed! Not allowed!

  27. #27
    Lifetime Member Enzo's Avatar
    Join Date
    May 2006
    Location
    Lansing, Michigan, USA
    Posts
    31,785
    Thumbs Up/Down
    Received: 1,655/7
    Given: 0/0
    Rep Power
    54
    Adaptors are in no way generic or universal, though many people assume they are... like your buddy.

    Most gear nowdays is labeled for just what power it needs. But when Pignose made the amp, it was assumed you would use the Pignose power adaptor. We know now from the schematic what it needs to be, but if you use the proper Pignose item, then you don't NEED to know what it spits out, all you need know is that it is the right one for the job.

    Not all makers get this for that matter. I remember some little MIDI acessory many years ago that came through the shop. They had tried the wrong adaptor and blown it up. In the repair game, this is not a rare type repair. Little Boss effects pedals for example will blow up the little protective zener diode if polarity is backwards or AC is applied. So I called the company that made the thing to ask what parts commonly fried when reverse power was applied. I also wondered to them why did they not add a protective diode for just that reason. They responded, "Oh no, only use our adaptor." Yes, I know that I replied, but when some nut uses the wrong kind, what typically blows up? "Oh no, don't use the wrong kind." Took me a while to get through to them that regardless of what we all are SUPPOSED to do, not everyone does it, and wrong power adaptor is something they should expect to happen to their products. And while there is no guarantee, many products have a fairly predictable failure mode under those circumstances.

    We are always glad when things work out around here, thanks the other guys for the schematics and insights as well.

    0 Not allowed! Not allowed!

  28. #28
    Junior Member
    Join Date
    Aug 2008
    Posts
    10
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    As i have already mentioned in a previous post, i have quite literally been blown away by this foray into solid state circuitry.
    I cant thank you all enough for all the suggestions and schematics, it only leaves me to apply the brain to the technology and letting you all know the outcome.
    Once again thanks to everybody.

    Larwood.

    0 Not allowed! Not allowed!

  29. #29
    Member
    Join Date
    Jul 2008
    Posts
    21
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Larwood, if you get that pig up and flying again. There is a really cheap and easy mod for the Pignose. Almost everyone that I know has fallen in love with the thing at 1/2 battery life. The same Tone can be achieved with the wall-wart PS by taking and wrapping the dc cable around a ferrite core. Just keep wrapping until you have the tone that you?re after. The mojo is in the turns, I don't question why and how some things seem to work, they just do. Have Fun

    Doug

    0 Not allowed! Not allowed!

  30. #30
    Junior Member
    Join Date
    Aug 2008
    Posts
    10
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0

    Wink

    Thanks Doug,
    I'll definitely try that, i have even thought of having an onboard wart so's there would always be a permanent power supply.
    But at this moment in time i have arrived at the conclusion that the resistor that burnt out is the bleed resistor between the two 324 transistors, 1R-1W Carbon. Now i cant say that is the correct resistor , because although all the other resistors are original ( white insulation paint on the legs ) only 11 of the 18 resistors tie up with the schematic. I've searched the case for more clues as to the age, and where the 9v input is , is a stamped date, that looks very much like 14 APR 1978. Now the other schematic that was posted by Teemuk, shows an 8.2R resistor in the bleed off..
    But most of all , until I've located the transistors i wont be going ahead with the rebuild in case there was a backwash of damage to the other components before the resistor burnt out.
    As i said in other posts I'll keep everybody up with the progress as i go along. Because along with all the help I've received from the Forum WE CAN'T FAIL CAN WE.

    0 Not allowed! Not allowed!

  31. #31
    New Member
    Join Date
    Dec 2008
    Posts
    3
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Quote Originally Posted by Borg54 View Post
    . There is a really cheap and easy mod for the Pignose. Almost everyone that I know has fallen in love with the thing at 1/2 battery life. The same Tone can be achieved with the wall-wart PS by taking and wrapping the dc cable around a ferrite core. Just keep wrapping until you have the tone that you?re after. The mojo is in the turns, I don't question why and how some things seem to work, they just do. Have Fun

    Doug
    Noob translation request: "wall-wart PS" - the AC adaptor? Ferrite core - a magnet or just iron? Thanks.

    0 Not allowed! Not allowed!

  32. #32
    New Member
    Join Date
    Dec 2008
    Posts
    3
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Quote Originally Posted by Cagey View Post
    Noob translation request: "wall-wart PS" - the AC adaptor? Ferrite core - a magnet or just iron? Thanks.
    OK figured out the WW. I haven't seen this mentioned anywhere else. Does anyone else have another reference to this trick?

    I found a "Dying battery simulator" - another way to achieve the same effect?

    http://beavisaudio.com/Projects/DBS/

    0 Not allowed! Not allowed!

  33. #33
    New Member
    Join Date
    Apr 2009
    Posts
    1
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Mybe this is a dead thread, but I have a pignose 7-100 that I bought in Japan in the early 90's. I just started using it again and was looking into the power situation as far as adapters and batteries go.
    Just to confuse things, the Korg PS I used from Japan had a negative tip, positive ring. The shop sold me a little pigtail adapter with the 3.5mm plug on it that reversed the polarity. All seemed fine and at the time I did not know that the pigtail reversed the polarity. The amp worked so I never even thought about it. But if you take the amp apart a red wire is connected to the ring and a green wire is set up on the tip.
    Go figure.
    I have actually tried a US PS with positive tip, negative ring and used the same little pigtail with the pignose and it still worked.
    So what gives?
    Pretty simple really. You have to go with what the amp wiring says and I am going to have to assume that the red wire meant positive ring.
    I am going to build a little external battery supply for NO HUM and longer playing time with the amp.
    First post.

    0 Not allowed! Not allowed!

  34. #34
    New Member
    Join Date
    Aug 2009
    Posts
    1
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0

    Bumping this thread back to life

    Hi
    I don't know too much about electronics, but given the interest in the Pignose 7-10, I thought I'd mention that for a while I've been collecting and interpreting the various schematics, with a view to posting a schematic of a close-to-original (Silicon BJTs) version of the amp. This is almost complete, but I'm not quite sure about the driver and output transformers. The driver seems to be about 2:1 (about 1k:500CT ?). Some schematics show a resistance of about 70 ohms on the secondary, which suggests a 400 to 1k ohm secondary. The output transformer in older amps seems to be a step down (48:8 ohms ?), like the old push-pull Mullard-design radio amps (discussed above). However, I suspect that the more modern output devices (TIPs) could handle lower ratios (8:8) and together with the lower emitter resistors, would put out more power (e.g. the 5W claimed). With a 48:8 transformer, the maximum power achieved seems to be about 1.5 W (according to my spice simulations).

    If anyone has details about the transformers (DC resistance or impedance, overall size, core size, path length) I would be very grateful to have it. If anyone has a dead pignose and is interested in selling it, I would also be interested.

    Thanks

    PS the emitter resistor varies in different schematics. This isn't surprising, given that the output trannies can be old, low-power Ge dvices (needing that 8.2 ohm resistor), or modern TIP41s (that seem to have a 2.7, 2.2 or 1 ohm resistor. 2.2 ohms seems a good compromise in my spice simulations.)

    0 Not allowed! Not allowed!

  35. #35
    New Member
    Join Date
    Dec 2009
    Posts
    1
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    I have been fortunate enough to own a very early Pignose for the last 15years, handmade and with a branded serial number, made by the inventors Richard Edlund and Walter Kimbell, with their address and phone no. (at the time), and a hand written dedication to the artist concerned.
    It is one of 500 or so that were handmade and given to various name guitar players and bands to promote their invention at the time.
    My question is, does anyone know anything about these very early handmade Pignose amps, there is a reference on the internet to one of them, no.064, that was given to Keith Richards of the Rolling Stones, but little else. The one one I've got pre-dates no.064.

    Any information would be most appreciated, DavidW.

    0 Not allowed! Not allowed!

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Original Pignose 5 inch speaker load???
    By imusbnutz in forum Maintenance, Troubleshooting & Repair
    Replies: 15
    Last Post: 12-10-2009, 07:52 PM
  2. Adding a PIgnose G40V standby switch
    By scottme in forum Mods & Tweaks
    Replies: 22
    Last Post: 12-20-2008, 11:00 AM
  3. Pignose G40V mods
    By tubetonez in forum Mods & Tweaks
    Replies: 0
    Last Post: 01-09-2008, 05:09 PM
  4. Slo-100
    By chunkitup in forum Maintenance, Troubleshooting & Repair
    Replies: 4
    Last Post: 12-13-2006, 02:18 AM
  5. Pignose 30/60
    By paulh in forum Maintenance, Troubleshooting & Repair
    Replies: 0
    Last Post: 08-02-2006, 03:37 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •