Page 1 of 2 12 LastLast
Results 1 to 35 of 36

Thread: Ashdown Five-Fifteen 100w combo keeps blowing fuses. Help me?

  1. #1
    Member
    Join Date
    Jun 2010
    Location
    Bainbridge Island
    Posts
    38
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0

    Ashdown Five-Fifteen 100w combo keeps blowing fuses. Help me?

    So as the title says my Ashdown Five-Fifteen 15" 100w combo amp blows it's fuse immediately after being turned on. The amp is solid state, so I can't do my usual and blame it on the tubes

    I should mention here that by fuse I mean all 3 fuses; the main fuse and the 2 internal PCB-mounted fuses.

    Unfortunately I realize this symptom could mean almost literally anything at this point, so I need some help narrowing down and getting to the bottom of this. I would like at some point to be able to use this amp again instead of just having it as a fuzzy nightstand

    Everyone's help is greatly appreciated. This forum has helped me fix an amp before, the know-how is definitely floating around here, I just need some help.

    Thanks!

    0 Not allowed! Not allowed!

  2. #2
    Lifetime Member
    Join Date
    May 2006
    Posts
    4,451
    Thumbs Up/Down
    Received: 446/1
    Given: 3/0
    Rep Power
    21
    A lot depends on what you can do safely.

    Do you already know how to work inside an amp with the AC power connected to it and turned on safely? If you don't your options are limited.

    0 Not allowed! Not allowed!

  3. #3
    Senior Member Euthymia's Avatar
    Join Date
    May 2006
    Location
    Alameda, CA, USA
    Posts
    267
    Thumbs Up/Down
    Received: 1/0
    Given: 0/0
    Rep Power
    14
    First, to debug this, you'll need a lightbulb limiter.

    The first things to check on instant fuse blow on a SS are the power transistors, then the power supply rectifier(s). Those can often be tested in-circuit using the diode test function of a DMM.

    If you get a dead short between any two terminals of a power transistor or rectifier diode or bridge, pull it and test it again.

    0 Not allowed! Not allowed!

  4. #4
    Lifetime Member Enzo's Avatar
    Join Date
    May 2006
    Location
    Lansing, Michigan, USA
    Posts
    32,950
    Thumbs Up/Down
    Received: 2,266/7
    Given: 0/0
    Rep Power
    55
    What RG said, safety is important.

    By far the most likely reason for blowing fuses is shorted power transistors. The next thing on the list would be rectifiers, and they are way down the list from the transistors.

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

  5. #5
    Member
    Join Date
    Jun 2010
    Location
    Bainbridge Island
    Posts
    38
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    The amp has 3 power transistors, two TIP142 and one TIP31c. To be honest, I'm not sure what readings indicate what when testing a transistor so I'll just put them up here.

    Putting the red cable of my DMM onto the middle terminal, I measured the DMM's black cable to the left terminal and got:
    TIP142 (the first one) 1848
    TIP31c 1744
    TIP142 (the second one) 704

    Going the other direction, with the DMM's red cable still on the center but with the DMM's black going to the right terminal of the transistor, I read
    TIP142 (first) 011 (no decimal, just what the display read)
    TIP31c 1605
    TIP142 (second) 004

    So... I don't know if that is how you are supposed to measure these things but that's what I did. If this is wrong, correct me and I'll redo it.
    Meanwhile... onto the rectifier

    0 Not allowed! Not allowed!

  6. #6
    Member
    Join Date
    Jun 2010
    Location
    Bainbridge Island
    Posts
    38
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    So for the rectifier I measured each of the adjacent pairs of terminals, reading from 540 - 570. Again, I don't know what that means but for none of these readings have I gotten a short or broken connection.

    P.S. thank you all for the safety warnings. I am cautious by nature, so I keep pretty safe working on things like this and know when it is time to quit when things get over my head.

    0 Not allowed! Not allowed!

  7. #7
    Lifetime Member Enzo's Avatar
    Join Date
    May 2006
    Location
    Lansing, Michigan, USA
    Posts
    32,950
    Thumbs Up/Down
    Received: 2,266/7
    Given: 0/0
    Rep Power
    55
    I haven't dug out the schematic yet, but could one of those TIP142s be a TIP147 instead?

    When we look at the three legs of those transistors screwed to the heat sink, we could call the legs 1,2,and 3. But what they really are is base, collector, and emitter, or B-C-E. Left to right.

    So it looks like from the center to the right, or C to E, you have a very low resistance. A collector to emitter short, we'd say. That generally means shorted. Those transistors must be removed from the board. We then test each again to verify the part itself has the problem instead of something else inside the amp fooling us. And then either the good checked part is installed back or a new part is installed.

    If one is a 142 and one is a 147, it is VERY important which one goes where. Also, you will probably find a mica square under the transistor and a plastic washer around the screw. These insulate the part from the metal heatsink, and are VERY important as well.

    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
    Jun 2010
    Location
    Bainbridge Island
    Posts
    38
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    You're right, the one on the right (the last one I listed) is a TIP147.
    Thank you for your help!

    One last question though...
    for future reference, what should the collector/emitter read resistance-wise?

    0 Not allowed! Not allowed!

  9. #9
    Lifetime Member
    Join Date
    May 2006
    Posts
    4,451
    Thumbs Up/Down
    Received: 446/1
    Given: 3/0
    Rep Power
    21
    If you're sure you can do this without electrocuting yourself,
    (1) put together a lightbulb limiter. It will pay for itself in fuses you don't have to buy and hours you don't have to spend.
    (2) divide and conquer; open the connections between filter caps and rest of the amp. If the fuse does not blow, it's in the amp. If it does blow, it's in the power supply and no amount of squinting power transistors will make it work.
    (3) If 2 shows it's in the amp, check the transistors for shorted, including shorted to chassis/heatsink. Enzo's comments are on target, as usual. Shorted transistors will show nearly zero ohms if they're shorted. Testing has to be done with it disconnected from the rest of the circuit to mean much.
    (4) there are other things. These are just the first places to look.

    0 Not allowed! Not allowed!

  10. #10
    Member
    Join Date
    Jun 2010
    Location
    Bainbridge Island
    Posts
    38
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Yeah, I'll put together a lightbulb limiter (sounds like something I'll be using fairly frequently) and go through the steps you outlined. I'll do that sometime in the next week and see how that goes... fingers crossed...

    0 Not allowed! Not allowed!

  11. #11
    Member
    Join Date
    Jun 2010
    Location
    Bainbridge Island
    Posts
    38
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Well, I pulled the TIP142 and the TIP147 and you're right; they're shorted across the collector-emitter.

    Now, I have a new TIP142 and TIP147 in my hand, but I am reluctant to stick them in the amp without knowing why they blew in the first place. I don't want them frying on me right when I stick them in there again. So could anybody spell out for me what probably happened? The amp was on loan to a friend when it blew.

    0 Not allowed! Not allowed!

  12. #12
    New Member
    Join Date
    Jul 2010
    Posts
    4
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    I was the service manger for Ashdown in Canada for three years. The 5-15 commonly blew output devices. There is a mod as well, depending on age. If it has 0.22ohm emitter resistors it requires the mod, which includes replacing the emitter resistors with 0.33ohm as well as bias circuit changes. sorry, can't recall exactly what needed to be done. Ashdown are reasonable folks, give them a call, they should help.

    0 Not allowed! Not allowed!

  13. #13
    Don't forget the joker g1's Avatar
    Join Date
    Feb 2010
    Location
    Canada, somewhere north of Fargo
    Posts
    12,360
    Thumbs Up/Down
    Received: 2,031/24
    Given: 5,166/11
    Rep Power
    24
    "So could anybody spell out for me what probably happened? The amp was on loan to a friend when it blew." 'Nuff said, this is surely one of the most common causes of amp fialure.
    Perhaps pushing the amp hard or trying to hook up extra speakers. Or maybe just coincidence. Check the speaker to make sure it still works.
    See post above regarding mod, the emitter resistors are larger and should be near the output transistors. Make sure they are still ok and see if it needs the mod or not.

    0 Not allowed! Not allowed!
    Last edited by tboy; 11-30-2010 at 08:59 AM. Reason: fixed smilie
    "Everything is better with a tube. I have a customer with an all-tube pacemaker. His heartbeat is steady, reassuring and dependable, not like a modern heartbeat. And if it goes wrong he can fix it himself. You can't do that with SMD." - Mick Bailey

  14. #14
    Member
    Join Date
    Jun 2010
    Location
    Bainbridge Island
    Posts
    38
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    @Anodyne Thanks for the tip! Unfortunately, I believe I have the 0.33 ohm resistor version. I have emailed Ashdown and am waiting to see what they will have to say.
    @g-one the speaker is still good, and the output transistors are definitely fried for sure; pulled them out and found the collector-emitter had shorted. So hopefully this mod will be the key (and with any luck Ashdown will provide me with the info I need to do said mod!)

    Fingers crossed!

    0 Not allowed! Not allowed!

  15. #15
    Member
    Join Date
    Jun 2010
    Location
    Bainbridge Island
    Posts
    38
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    I did get a hold of an Ashdown representative, who was fantastically helpful. I am pretty sure I fixed the problem (with his (and your!) invaluable help, of course!) and I'll post what I did after a couple of days, just to make sure the amp keeps truckin' and in case anyone else goes to scour the internet to fix this same problem.

    0 Not allowed! Not allowed!

  16. #16
    New Member
    Join Date
    Aug 2010
    Posts
    3
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Quote Originally Posted by docSanchez View Post
    I did get a hold of an Ashdown representative, who was fantastically helpful. I am pretty sure I fixed the problem (with his (and your!) invaluable help, of course!) and I'll post what I did after a couple of days, just to make sure the amp keeps truckin' and in case anyone else goes to scour the internet to fix this same problem.
    G'day docSanchez, I'm just wondering how you got on with your Amp repair. I have the same problem with my Five Fifteen, i.e. TIP142 and TIP147 have shorted between the Collector and Emitter. The emitter resistors are 0.22 Ohm. I have emailed Ashdown to see if they could send me details of the mod but I've heard nothing back. Are you able to post details of the modification you did to your amp. Thanks alot mate

    0 Not allowed! Not allowed!

  17. #17
    Member
    Join Date
    Jun 2010
    Location
    Bainbridge Island
    Posts
    38
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Well, for a start the emitter resistors are supposed to be 0.33 ohm. The only other problem on my amp is there is apparently supposed to be a jumper from R27 to the emitter of the TIP142 (TR2).

    I used the contact hole for the emitter of the BDX53 (which isn't there in the Five Fifteens) for one end of the jumper, as this connects to the end of R27 and squeezed the other end of the jumper into the hole for the emitter of the TIP142 and soldered those two together. It would appear R27 leads into a circuit protection system, so if your amp (like mine) is lacking this connection then check for that.

    Other than that, I haven't had to do anything. The only reason I never did a wrap-up post here is because (like an idiot) I fried my new TIP142 on accident and hadn't ordered a spare, so I had the amp fully functional for a couple of hours and then I blew it up again due to my endless need for tinkering and SCIENCE. So I hope this helps.

    0 Not allowed! Not allowed!

  18. #18
    New Member
    Join Date
    Aug 2010
    Posts
    3
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Thanks very much for the quick response docSanchez, much appreciated. If this is a common fault with the Five Fifteen amp you would think that Ashdown should doing a recall to fix it, even if they are out of warranty.

    I'll try modifying my Amp this week and post back the results, thanks again for your help.

    0 Not allowed! Not allowed!

  19. #19
    New Member
    Join Date
    Aug 2010
    Posts
    3
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    G’day docSanchez,

    I am just posting back the results from the modifications outlined above, unfortunately the amp blew again after about 5 hours of use with the same results as before i.e TIP142 and TIP147 have shorted between the Collector and Emitter which cause the fuse to blow straight away on power up.

    I managed to track down one of the local Ashdown reps and he sent me step by step instructions, good news is after doing these modifications the Amp now works perfectly. Here’s what to do:

    1. Removed and discarded TR2, TR3, TR8 and TR9, then clean off the heat sink.
    2. Fit a TIP142 in place of TR2 and a TIP147 in place of TR9 using Silicon pads (or Mica washer and heatsink compound ). Do not fit any components for TR3 and TR8.
    3. Replace R22 and R38 resistors with the new 0R33 ( 6 watt ) resistors
    4. Please ensure there are no resistors fitted in positions R24 and R36.
    5. Fit a wire link between the solder pad where TR3 and R24 join; and the solder pad where TR2 and R22 join..
    6. Change resistor R30 from 2K2 to 1K5 .
    7. Turn the amp on with an 8 ohm load connected to the output, but with no input.... measure the voltage across R22 and R38 with a DC milli-voltmeter and adjust preset P1 for 3 mVolts on whichever is the lower, they should be between 2.5 and 3.5 mVolts.
    8. Inject a signal into the input and test as usual, then play.

    Hope this information helps.

    0 Not allowed! Not allowed!

  20. #20
    Member
    Join Date
    Jun 2010
    Location
    Bainbridge Island
    Posts
    38
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    This is a fantastic resource for people with older Five-Fifteens as it is a clear, step-by-step instruction to bring the amp up to standards and to a place where it will stop blowing itself up.
    Sadly, my amp already has everything you already mentioned as it is new enough ;(
    The only thing it didn't have was the wire link which I added in an earlier post.

    So what I have found is I have a new problem: my transformer is shot. I have no earthly idea how this happened; but one of the solder terminals on the transformer came out from the winding.

    Can anybody help me find a new/replacement transformer? The amp tech told me the "transformer is a 100VA unit with one centre tapped secondary ( 31 - 0 - 31 volts )..."
    Unfortunately, I am still pretty new to transformers. On the transformer that came out of the amp it is labeled

    120V - 100V - Fuse
    YW PT-Five-Fifteen-100/120V
    31V - 0v - 31V

    These are the transformers I found:
    Hammond 166E30 166E30 Hammond Manufacturing Transformers
    Hammond 166F30 166F30 Hammond Manufacturing Transformers
    Hammond 166G30 166G30 Hammond Manufacturing Transformers

    I can't tell the difference between any of them. There's also this one:
    Hammond 165530 http://www.alliedelec.com/search/pro...6250#tab=Specs

    I don't think the last one is what I need, (also it's more expensive) The only thing that confuses me about the first 3 transformers is that they have 5 cables going out: 2 for the primary winding and 3 for the secondary winding; both ends and a center tap. The transformer that was actually in my amp has 6 cables/junctions coming out from the transformer, and though one of them was unused and covered with heat shrink tubing, it still makes me pause.

    Any transformer experts out there willing to give me a hand?

    0 Not allowed! Not allowed!

  21. #21
    New Member
    Join Date
    Nov 2010
    Posts
    2
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Quote Originally Posted by reddwarfer29 View Post
    1. Removed and discarded TR2, TR3, TR8 and TR9, then clean off the heat sink.
    2. Fit a TIP142 in place of TR2 and a TIP147 in place of TR9 using Silicon pads (or Mica washer and heatsink compound ). Do not fit any components for TR3 and TR8.
    3. Replace R22 and R38 resistors with the new 0R33 ( 6 watt ) resistors
    4. Please ensure there are no resistors fitted in positions R24 and R36.
    5. Fit a wire link between the solder pad where TR3 and R24 join; and the solder pad where TR2 and R22 join..
    6. Change resistor R30 from 2K2 to 1K5 .
    7. Turn the amp on with an 8 ohm load connected to the output, but with no input.... measure the voltage across R22 and R38 with a DC milli-voltmeter and adjust preset P1 for 3 mVolts on whichever is the lower, they should be between 2.5 and 3.5 mVolts.
    8. Inject a signal into the input and test as usual, then play.
    Great post guys, thank you.

    I'd like to point out that in the last step when you measure across the output resisters R22 and R38 to adjust P1 to achieve 3mv across the lowest value resistor, the voltages will be opposite polarity. I emailed Ashdown and they promptly confirmed that is correct; just treat it as absolute voltage, regardless of polarity.

    Thanks again for this thread, my Five Fifteen amp is now working again.

    0 Not allowed! Not allowed!
    Last edited by Markcm; 11-28-2010 at 05:43 PM. Reason: correction

  22. #22
    Lifetime Member Enzo's Avatar
    Join Date
    May 2006
    Location
    Lansing, Michigan, USA
    Posts
    32,950
    Thumbs Up/Down
    Received: 2,266/7
    Given: 0/0
    Rep Power
    55
    Hi Markcm, welcome to the forum.

    You are right to point out that polarity is important.

    However in this case, the requirement is to measure the voltage across a part. Unless you also specify which end is which, there will not be a polarity. In other words of there is 1 volt across a resistor, it will be 1 volt regardless of which direction you take the reading. One end will be positive with respect to the other end. Of course then one end is negative with respect to the other end.

    In these amps, voltages are usually measured with respect to ground. SO if one end is at zero, and the other end at +5mv, then we can say there is +5mv at the one end, and 5mv across the part. Reading the voltage across the resistor is just a way to infer the current flowing through it. If you swap your leads, the polarity reverses.

    I realize I am being very picky about terminology, and someone may well disagree with me.

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

  23. #23
    New Member
    Join Date
    Nov 2010
    Posts
    2
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power
    0
    Quote Originally Posted by Enzo View Post
    Hi Markcm, welcome to the forum.

    You are right to point out that polarity is important.

    However in this case, the requirement is to measure the voltage across a part. Unless you also specify which end is which, there will not be a polarity. In other words of there is 1 volt across a resistor, it will be 1 volt regardless of which direction you take the reading. One end will be positive with respect to the other end. Of course then one end is negative with respect to the other end.

    In these amps, voltages are usually measured with respect to ground. SO if one end is at zero, and the other end at +5mv, then we can say there is +5mv at the one end, and 5mv across the part. Reading the voltage across the resistor is just a way to infer the current flowing through it. If you swap your leads, the polarity reverses.

    I realize I am being very picky about terminology, and someone may well disagree with me.
    I'm sorry but I don't think your comments aid to this five-fifteen amp repair discussion at all. My intent was to help others who may have ended up here, possibly from a google search, trying to fix their five fifteen amp. No offense intended but your comments about voltage, current, swapping leads and "reversing" polarity neither aid to this repair or in my opinion are very clear/concise. My main goal was to point out that these two resistors share a common point in the circuit so they will most likely be measured with the same "relative" reference which will result in opposite relative polarities which I feel is an important detail and will help clarify if one has been "successful" with their repair. That was my intent.

    I don't mean to step on your toes as a major contributor to this forum (all respect for your contributions) anymore than you intended to step on mine although I feel like you derailed my comment which was short, accurate, relevant, and simply intended to assist any and all with a successful Five-fifteen amp repair.

    0 Not allowed! Not allowed!

  24. #24
    Lifetime Member Enzo's Avatar
    Join Date
    May 2006
    Location
    Lansing, Michigan, USA
    Posts
    32,950
    Thumbs Up/Down
    Received: 2,266/7
    Given: 0/0
    Rep Power
    55
    I apologize if you felt I intruded on your comments, not my intent at all.


    My intent was to explain to others reading along, essentially what you report Ashdown as telling you - "just treat it as absolute voltage, regardless of polarity." I used different terms in hopes someone who doesn;t get it one way, might get it another way. Much as you added to the previous post by reddwarfer with further explanation.

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

  25. #25
    Senior Member
    Join Date
    Jul 2009
    Location
    Phoenix, AZ
    Posts
    483
    Thumbs Up/Down
    Received: 1/0
    Given: 0/0
    Rep Power
    11
    Good to see you're back, Enzo. We missed you for a few days here. Well, SOME of us missed you.

    0 Not allowed! Not allowed!
    ST in Phoenix

  26. #26
    Senior Member
    Join Date
    Dec 2011
    Location
    Pretoria, South Africa
    Posts
    693
    Thumbs Up/Down
    Received: 8/0
    Given: 0/0
    Rep Power
    9
    Anyone have schematic for me please!!!!????

    0 Not allowed! Not allowed!

  27. #27
    Supporting Member Jazz P Bass's Avatar
    Join Date
    Dec 2008
    Location
    Wernersville, PA
    Posts
    13,068
    Thumbs Up/Down
    Received: 609/3
    Given: 314/0
    Rep Power
    28
    http://music-electronics-forum.com/a...ss-amp-sch.jpg

    Here is a doc that I copied off of a post in 2010.
    It has to do with modding the output section on older 515's.
    Attached Files Attached Files

    0 Not allowed! Not allowed!
    Last edited by Jazz P Bass; 07-28-2014 at 04:41 PM.

  28. #28
    Senior Member
    Join Date
    Dec 2011
    Location
    Pretoria, South Africa
    Posts
    693
    Thumbs Up/Down
    Received: 8/0
    Given: 0/0
    Rep Power
    9
    Anybody have a schematic???

    0 Not allowed! Not allowed!

  29. #29
    Old Timer J M Fahey's Avatar
    Join Date
    Oct 2007
    Location
    Buenos Aires, Argentina
    Posts
    11,753
    Thumbs Up/Down
    Received: 1,885/23
    Given: 1,463/35
    Rep Power
    27
    Quote Originally Posted by diydidi View Post
    Anybody have a schematic???
    Here it is

    WARNING: THE VERBAL (WRITTEN) INSTRUCTIONS DO *NOT* MATCH PARTS NUMBERING IN THE SCHEMATIC.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	Ashdown 515 Bass Amp sch.gif 
Views:	1334 
Size:	310.4 KB 
ID:	29905  

    1 Not allowed! Not allowed!
    Last edited by J M Fahey; 08-06-2014 at 03:12 AM.
    Juan Manuel Fahey

  30. #30
    Old Timer J M Fahey's Avatar
    Join Date
    Oct 2007
    Location
    Buenos Aires, Argentina
    Posts
    11,753
    Thumbs Up/Down
    Received: 1,885/23
    Given: 1,463/35
    Rep Power
    27
    UPDATE:

    I searched my small Ashdown schematic database and found one which matches written instructions.

    It is NOT labelled "515" BUT itīs quite common for manufacturers to build a few of the "new" models using leftover parts of the earlier ones they replace, specially since often "new" models are just cosmetic rehashing of earlier successful ones, simply under pressure from Marketing Department guys.
    As in: "Hey !!! , we need FIVE new models for Cristmas (NAAMM/Frankfurt) , we canīt push las year models !!!!" .

    So here it is the Backpack, with that silly mixture of BDX and TIP transistors.
    What were they trying to do?
    Emulate Mesaīs dubious "Simulclass" tube mixture?
    Attached Files Attached Files

    0 Not allowed! Not allowed!
    Juan Manuel Fahey

  31. #31
    Supporting Member Jazz P Bass's Avatar
    Join Date
    Dec 2008
    Location
    Wernersville, PA
    Posts
    13,068
    Thumbs Up/Down
    Received: 609/3
    Given: 314/0
    Rep Power
    28
    Juan, can you 'zip' the file?
    It's not loading.

    0 Not allowed! Not allowed!

  32. #32
    Old Timer J M Fahey's Avatar
    Join Date
    Oct 2007
    Location
    Buenos Aires, Argentina
    Posts
    11,753
    Thumbs Up/Down
    Received: 1,885/23
    Given: 1,463/35
    Rep Power
    27
    OK.
    Itīs the so labelled Ashdown Backpack which matches the Mod instructions.
    Also added the picture of a PCB , labelled "65" which seems to match that schematic and description.
    As I said before, itīs common for manufacturers to mix and match a just couple "ingredients" and come out with lots of "different" products.
    By the way what Leo Fender and Mc Donaldīs did, with HUGE success

    The same Ashdown PCB seems to be used for different power amps, probably 15 and 30W ones with smaller ŋTO220? BDX transistors, 65W ones with larger TIP and *maybe* 80/100W ones with all 4 .
    Which is a problem because the TO220 can not dissipate the same power as the larger TIP, yet all 4 have same drive and emitter resistors. What were they thinking?
    Mismatching not by chance but by DESIGN

    What d Saint Enzo ancient teachings say about not mixing even same brand different batch transistors?
    Attached Files Attached Files

    0 Not allowed! Not allowed!
    Juan Manuel Fahey

  33. #33
    Old Timer oc disorder's Avatar
    Join Date
    Jul 2006
    Location
    Land Down Under
    Posts
    1,268
    Thumbs Up/Down
    Received: 4/1
    Given: 1/0
    Rep Power
    15
    Some pictures here so I thought may help to link this page as search doesn't seem to pick this up
    "looking for an ashdown five fifteen schematic"

    http://music-electronics-forum.com/t33661/

    0 Not allowed! Not allowed!

  34. #34
    Senior Member
    Join Date
    Dec 2011
    Location
    Pretoria, South Africa
    Posts
    693
    Thumbs Up/Down
    Received: 8/0
    Given: 0/0
    Rep Power
    9
    Does this mod apply to the Perfect Ten 30W combo too??
    It also has the Darlingtons in there.

    0 Not allowed! Not allowed!

  35. #35
    Senior Member
    Join Date
    Dec 2011
    Location
    Pretoria, South Africa
    Posts
    693
    Thumbs Up/Down
    Received: 8/0
    Given: 0/0
    Rep Power
    9
    OK. Its official. Contacted Ashdown...
    The mod does not apply to other Ashdown amps with similar circuitry/ boards, but only to the 5-15..

    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. Silly Doubt JCM900 Dual Reverb 2x12 Combo 100W (5881)
    By Lee_ranaldo in forum Maintenance, Troubleshooting & Repair
    Replies: 5
    Last Post: 06-03-2010, 11:23 PM
  2. Ashdown 500 EVO blowing fs3 fuse
    By 01redcobra in forum Maintenance, Troubleshooting & Repair
    Replies: 6
    Last Post: 07-25-2009, 11:58 PM
  3. Ashdown mag 300 combo amp, quit on me.
    By fasttimes in forum Maintenance, Troubleshooting & Repair
    Replies: 2
    Last Post: 04-04-2009, 09:15 PM
  4. blowing fuses on a ss bass combo
    By black_labb in forum Maintenance, Troubleshooting & Repair
    Replies: 6
    Last Post: 12-15-2007, 11:40 AM
  5. Blowing fuses...
    By riscado in forum 5 E 3
    Replies: 7
    Last Post: 08-21-2006, 03:06 PM

Tags for this Thread

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
  •