Odd normal vol channel..

[stokes]

No need to post the volts if MJWB said they are okay,then I am sure I wont see anything there.I just went down and checked mine as you described and when plugged into the bright input with that vol on zero or off and turning up the normal volume I get a dull,bassy muddy tone with very little volume and I have to wonder if this is what you have been describing yours sounds like.Again I have to say that speaker should be okay with that amp,I dont think a speaker change is going to help,the first speaker I had in mine had an Eminence Legend and it was fine.A 5E3 that is wired correctly is going to sound decent if not "ideal",and may require some tweaking to get it to your liking,but it will definately not exhibit what you are describing.I still have strong suspicions about your inputs,I hate to sound like a broken record about these inputs but you did have a problem earlier there,to simplify things in that regard I would again suggest disconnecting all your inputs and wire just one input to the brite channel with a 1meg from the "hot" lug to ground,a 68k in series to the input grid of the 12AY7 and the shorting switch grounded.This will make your input as simple or basic as can be,if the amps response improves,you have your problem solved,if not you can move on to another stage as you have discounted that "stage" as the problem.Gotta go one step at a time,and starting at the beginning is the best way

[The Captain]

I did redo the inputs, so now no. 1 is tighter and a tad louder sounding than no.2 on each channel (all have 1M checked) but with your point taken on board Ill strip them to one each tmrw. As to your help re my Q above Mr. Stokes that muddy dull sound is exactly what I have- but it sounds just like this on normal input/ normal vol, or with this vol at 0 and bright vol at 2ish.. so Im nearly convinced then that its the way its meant to be. I noticed that the tone is brightest at 9 tailing off again up to very dull again at max on normal channel, is this the norm too?

So, if you and others suggest the speaker should be ok although Im only getting little at best blatty, hard overdrive even with either vols (or both vols) high -then could the OT could be a weakness? I also read a certain better quality 5y3gt's blurb.. 'good for low headroom' etc: I didn't think the rectifier was determinant of clean headroom, rather having 2 12ax7s was the idea on this.

Thanks for the advice all- frustrating as this has been Im much happier knowing I can spiel with intelligent advice in reply. Im very reluctant to give up on this- heck I even made a flight case for it- so Ill crack on again tmrw.

[MWJB]

To check your speaker (& eliminate from our enquiries), pull the jack from the chassis (amp off of course) and put a 9v PP3 battery accross the jack plug terminals, one terminal to the barrell of the plug, the other to the tip. On connection you should hear a definite crack, if you're in doubt as to whether you hear anything, or you just get a quiet, dull "tick" then maybe your speaker is suspect BUT, as Stokes says, an Eminence 125 should be absolutely fine for your amp if in proper working condition.

If the OT was the weakness I would expect a fuzzy, "radio" like tone with no cleans whatsoever. This is not what you have been describing.

5Y3 - different brands may result in differing final voltages (more volts = more headroom) and a different envelope of the note (intensity of attack & decay). lots of factors contribute to clean headroom, rectifier is just one of them.

Don't give up.

[Bruce / Mission Amps]

As to your help re my Q above Mr. Stokes that muddy dull sound is exactly what I have- but it sounds just like this on normal input/ normal vol, or with this vol at 0 and bright vol at 2ish.. so Im nearly convinced then that its the way its meant to be. I noticed that the tone is brightest at 9 tailing off again up to very dull again at max on normal channel, is this the norm too?

Assuming you are describing this condition accurately, nope, I still think something is not right.
However, the actual tone control is across the bright channel's volume pot so it's effectivness is limited, with respect to the normal channel volume pot.

The correct norm is this....the common cathode of both triodes of the 12AY7 allows the unused triode to be heard when plugged into the other channel and the two volume pots are wired in parallel, effecting each other's channel.

That unused channel, in a weird way, becomes a cathode driven preamp.
In other words, the common cathode resistor slightly modulates the unused channel's cathode by the signal from the one you are actually using.
Confusing?
Try this, plug into the bright channel and shut it's volume control down to zero.
Now, turn the normal channel's volume control up all the way and strum some chords (while plugged into the bright channel) and you will hear a low volume level, muddy tone that is about 1/4 the volume level of the actual channel you are plugged into, but there is very little treble response.

You can use this effect to alter the tone of the bright channel you are plugged into and this effect is part of the interactive volume controls peopole either love or hate.
In conjunction with the odd "cathode driven" preamp effect of the 12AY7 wiring, the two volume pots are also wired in parallel.
Signal is fed into the vol pots through their center lug, the wiper.
So when you turn the unused volume pot up while being plugged into the other channel, signal leaks over the top of the pot and you start loading down the "used" channel's signal path, shunting some of the audio to ground through the unused channel's volume control to it's 100nF coupling cap and over to the actual B+ supply filter cap, which is grounded.

[The Captain]

I think then I may be in the hate camp! Ive a better understanding of the pots now thanks Bruce. I'll look into that dual gang pot job I think (as per the s2 5e3); its also meant to help the quick ramping too- but this later- 1st I need to find out how/ if I can get any distortion with the useable bright channel. So
1. Im gonna ditch the plastic jacks for switchcrafts and install one each channel for the mo.
2. scratch my head again as to why barely any distortion/ check all wiring for 8th time.
3. ditch my mdf cab/ chipboard baffle (prototype) & make a pine cab/ ply baffle to help the general tone.
4. get this 5y3gt as it has 'good lower headroom' http://www.watfordvalves.com/product_detail.asp?id=94 ('sag' whats that?)
5. trim my beard.

here are my scribbled voltages:

Pin 3 (both pwr valves)= 389v/ 388v
Pin 4 screen= 341v
Pin 6 plate (preamp?)= 193v
Pin 1 plate= 155v
Power supply= 247v
Pin 6 (12ay7)= 126v
Pin 1= 121
Preamp cathodes= 2.04v, and 1.28v.

cheers, captain.

[MWJB]

Your lack of distortion isn't coming from the cab material.

Even the TAD 5Y3 should be giving you noticable break up, often 5E3 owners upgrade to 5V4 rectos (tighter still, more volts that you have) and the amps still grind plenty easy.

Sag is compression, a "squashy" sound, when you pick a note the internal resistances of the power supply & rectifier soften the initial attack, then as everything gets back up to spec, the note builds during the decay/sustain and the note appears to "bloom". With a 5Y3, std PT & filtering and cathode bias you should be getting this anyway.

Lower headroom means that it distorts at lower volume settings, even so, the 5Y3 that you have the amp should still be distorting.

Your not in the hate camp, we're all rooting for you. You've jumped in at the deep end and we all want to see you swim.

There must still be a fundamental wiring/component error, looking to change cabs, speakers, rectifiers etc is just muddying the water and drawing out the process. With the parts you have now a properly functioning 5E3 should be in there somewhere. The last thing you probably want to do is pull up the board, if your input jack swap doesn't reveal anything then this would be my next step.

[Colin]

Captain

Those voltages look in the right ball park and, as MWJB says, changing things like cab, rectifier etc won't solve your basic problem. I posted this on another of your threads to help with input jack wiring - so I hope I'm not butting in or anything.

Just scroll down slightly on this link to see an excellent description of input jack wiring (not mine!)

http://www.hoffmanamps.com/charts/CommonHookups.htm

Make sure you use the 4 x Switchcraft 12A (Tip/Switch/Sleeve) inputs.

Hope this helps

Colin

[The Captain]

(Partial) success! I stripped all the sockets out for one metal jack (2 lugger all I had) in the bright no.1.. now the tone/ response and sweetness came through better; before it sounded like a crap tranny amp- now a tube amp, responsive with sustain and a ringier fenderyness- so a good start. So then I popped another in the normal no.1.. bit better tone, but its still bass city/ unuseable- mixing vols bassed out things again. Gainwise (distortion) still not heard yet, BUT with an eq pedal level on max I can finally hear an overdriven tone: before this was only a slight 'blatty' break-up. Interestingly also, before as I measured powered down filter caps etc before a tweak they read 4-7V ish. Now the same points were ~0.5v could that tell a story?

Until I get some switchcrafts in at least I have a FULL ,very rich clean one input amp, and can see finally why blues players loved them. Tmrw and with much faffing Ill take the board up, and hopefully find a page 1 wiring mistake. Ive have grey whiskers in my beard now. thanks all- Captain.

[stokes]

Cap'n,as I have been saying,at least part of the problem was in the input wiring.I would advise just using one jack for the normal and one for the bright,as you are only going to use one at a time anyway.In both the 5E3's I have,I rarely use the normal input,with most guitars it is too bassy,only use it with a Telecaster.For the next step I would look over the volume/tone controls wiring.Dont use any EQ or other pedal,with a properly working amp,you wont need one,so using one while testing is only going to muddy the waters ,as MWJB has already pointed out.Your normal channel is going to be much bassier than your bright and as I said I find it undesireable with Humbuckers and only useful with something as shrill as a Tele.I dont fully understand what you are getting at with this description-"Interestingly also, before as I measured powered down filter caps etc before a tweak they read 4-7V ish. Now the same points were ~0.5v could that tell a story"?I am assuming you are saying you saw 4-7 volts at the main filter and now see .5v with the amp turned off.Is this ac volts or dc volts?Before what tweak?
If by being in the hate camp you are thinking that we have developed a hate for your problem,that is not the case at all,like MW says we are all rooting for you and I know for myself,it wil will be great to see you get this amp working,I know it is tough to decipher all the advice and pointers we are throwing at you,but stick with it,when you get this amp working I am sure you will be happy with it.I have yet to meet anyone who doesnt like this amp,the only complaint I have ever heard is that it doesnt have enough balls to cut thru a loud band.Once you get it working properly,we can start giving you ideas to tweak things like rectifiers and caps and speakers,but for now lets work with what you have and get it functioning right.Try the bright channel with both volumes turned up halfway,you should get some sweet overdrive,if not perhaps we have to look for some sort of oscillation,or a problem in the vol/tone circuit.

[The Captain]

Ive gone through all the replies here again, much fine info allround: today I checked wiring under board- all ok. The tone is better now with just one input each, still so full and bassy its impossible to turn up without a damn eq pedal's bass way down (the ONLY reason Im using the wretched thing). Almost taking a row of houses out (vol 8) to check for overdrive, there is some now tho harsh & totally unuseable as its so venomously loud, and with that bass.. I built a 5e3 as it has 'great overdriven tones at lower volumes'; I hate any pedals too. So as a useable amp its clean only and hugely bassy the last 2 things I was after.. but I still dig it cos I made it! but this of course will wear off soon.

Ive checked absolutely everything so many times now/ changed caps valves, pots and even rewiring my SG. So it is definitely, unequivocally all as should be and there's now't else I can do my beard now has food bits in. Captain.

[Steve Conner]

If you've not owned an old non-master-volume style tube amp before, it could just be a matter of expectations. When people say the 5E3 Deluxe gives good overdriven tone at lower volumes, they probably mean lower relative to a plexi-fronted Marshall or whatever They don't mean that you can get distorted tone from the amp itself at levels suitable for practicing at home. Even my 3 watt Selmer with one EL84 has the neighbours banging on my door if I crank it at home. You may not appreciate the full mojo of your amp's cranked tone until you've played it "venomously loud" in a band situation.

Most newer amp designs have some sort of master volume-like arrangement on their dirty channel to let you drive the preamp tubes into reasonable sounding distortion without cranking up the power amp and bombing the whole area. Even Fender's own Hot Rod Deluxe reissue did that. It doesn't have the mojo of a cranked power amp, but it is damn useful, even in a band, for those times when you need to keep your stage volume under control. You can get the same effect with your 5E3 by using a tube screamer-type drive pedal or a power attenuator between amp and speaker. If you don't like the thought of a stomp box full of yucky silicon, I have seen schematics for a DIY drive pedal that uses only tubes.

Can you record some sound clips of the amp? I'm sure if you posted sound clips here, the 5E3 experts would be pretty quick to tell you if there was anything wrong with it. But you may just be suffering from non-MV culture shock. I remember my first non-MV amp, a Treble'N'Bass 50. It would go deafeningly loud before it even started sounding a bit dirty. I ended up modding one of the channels to add an extra gain stage, so it would break up at quieter levels, but still have the option to use it the way it was. I lent it to a friend who refuses to use the modded channel, and just abuses the stock one with a Tube Screamer.

[The Captain]

Of course naiive I as may have been, 'lower volume' can mean different things (relative to *?). I was shocked at how loud this 15w is- previously, and why I progressed to this build, I modded Epi Vjnrs. At 5w I had a rough assumption a 15w would be approx twice as loud (ish); & with 2 vols knowing they mixed together I assumed a sort of MV config- wrong on both counts!! It seems 4x as loud & the whole normal channel Ill never use as its bass is overwhelming. I did manage to produce a decent distortion adding a great MV (at approx the two 220ks in this 5e3 config) on the wee Vjr: I wonder therefore, and realise it may be sacriligeous whether a circuit such as this can be introduced.. (from a babe of a diy fender Vibrothingy- it seems to be Bruce's MV idea too) http://i102.photobucket.com/albums/m...2/pi-m-vol.jpg .. or even whether the normal channel can be hooked directly to t'other channel so effectively one channel with 2 vols? I'll also look into adding a whole new tone circuit with a bass pot- but next year or so.. I am enjoying the amp now at least thanks to help here, its (big!) clean tone has definite character- so a big cheers all. Captain.

[stokes]

Cap'n,if you are using the .1mf coupling caps,I would suggest changing them to .02mf.I went to the .047 and then settled on the .02's to brighten things up and lose some of the muddiness present with the .1's.The normal channel is still quite "bassy" compared to the bright,but is more usable with the .02's.I also found the 5V4 rectifier and boosting the main filter to 40uf or better (dont remember but I might have 80uf for the first and 40uf for the screen,but it is at least 40 & 40) helped reduce the flabbiness.The interactive volume controls dont work like a MV at all.Turning the unused volume to about 1/2 full will scoop the mids and somewhat quiet the volume overall,but nothing at all like a MV.

[The Captain]

Coupling caps being the two .1ufs twds rhs of board? if so I did that 1st up.. along with left preamp bypass 25uf/1.5k to .68/1.5k all three made no discernable difference at all (?) another reason i took the board out and other checks etc. Should I keep the two .1uf in middle of board (my RS big yellow chaps) at this value?

[stokes]

All 4 of the .1 caps are coupling caps.I changed them all.There is also an .02 cap from the plate of the stage preceding the PI input grid,I changed that to .01.The .68 bypass cap will cut mids from that stage and lower the gain of that stage too much,I would put the 25uf back,this value will boost all the frequencies your guitar is putting out and makes for better gain in that stage.In my opinion the .68 cap will cause too much of a cut in the gain of the stage which will adversely affect the gain and response of the following stages.