Ambassador - Matchless Hotbox project

I just built a modded Ambassador (see below) that comports to the schematic I submitted in the previous post (but no B500K trim). I am not getting any output and it appears that the problem is with B+ voltage. I have taken readings at the points shown on the right below, dbl checked all component values on resistors/caps/inductor and swapped out the NE555. The 9vdc (+/-) readings are consistent with my Particle Accelerator, but the 19v (+/-) readings are all 250v (+/-) in the PA (UPDATE: the upstream side of C1 is also 19.1v so its just replicated throughout the rest of the circuit). Any suggestions?
Amb PCB DC30 mod.jpg Ambassador tshoot.jpg
 
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WRONG!!! I thought I had a 250v reading, but it was just a momentary blip. Here's what I'm getting. The NE555's came out of the same shipment. Could there be dodgy chips??? I notice I get the same reading on both sides of R4, but it measures 10K on the nose.
PSU.jpg
 
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You have two of the same 12AX7 daughter boards instead of a 12AX7 and 12AX7R, which means the pinout of your right tube is incorrect with what the circuit is expecting. Did I ship it to you like that, or did you order multiple things at a time and get them mixed up?
 
Came like this. I assume ur talking about the one that's NOT parallel wired? Would that effect the PSU?

Forget what I just said. . . . . the EZ90R is sitting in my Particle Accelerator that's not working!?!!?!? I notice that C2C is selling extra daughter boards. I'll order a couple more and correct the situation. I ordered at differnet times, but didn't start building until they were both sitting in my "in-box". Thx for the correction.

BTW, did you look at the layout enough figure if it would work as a DC30 clone?
 
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I finished my Ambassador this weekend and its sounds great! Very happy with it. Unfortunately I realized, that the hot channel is much less loud (and a little dull) than the clean one. (Not shure if this is the right spot to aks for some suggestions) This was my first tube-related project, so I have no idea, where to look. :) I checked for values (they are right) and shorts (there are none visible). So, whats next?
 
Anton K said:
I finished my Ambassador this weekend and its sounds great! Very happy with it. Unfortunately I realized, that the hot channel is much less loud (and a little dull) than the clean one. (Not shure if this is the right spot to aks for some suggestions) This was my first tube-related project, so I have no idea, where to look. :) I checked for values (they are right) and shorts (there are none visible). So, whats next?
Click to expand...
I saw your email, sorry I haven't replied yet. I've been meaning to plug in one of the units I built up to see what the volume difference is like between the two channels on mine. I don't remember it being a big difference, but how much of a difference are we talking? Any chance we could get a video?
 
Hi Vigilante,

no need for sorry. :) thought, could be a good idea, looking somewhere for suggestions. :) I am not a video-guy, but I made a soundfile - can you load it?
All pots ar on 12 o’clock. First the clean, than the hot channel …

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Ambassador_volume-difference.png
even with a fuzz in front of the ambassador:

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Ambassador_volume-difference_fuzz.png
 
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ok, good to know. :) Yes, of cause!
Meanwhile I assume a cold joint on the connections to the tube-board. Its so narrow, I have do remove some of the elements and try to resolder …
Hope, you’re not angry about my additional bypass …

IMG_1486.jpeg IMG_1487.jpeg IMG_1488.jpeg IMG_1489.jpeg IMG_1490.jpeg
 
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just "56"Edit: my DMM measures about 100pF

I have some 47pF (measures 90pF) and some 33pF (measures 50pF) shall I replace it?
 
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No, that's fine.
This pedal has a huge bass response, I have mine @ 9.00 if 7.00 is fully counterwise, the Treble is completely opposite being at 2.00 to 3.00.
The volume is huge in both channels being around 10.00 for Unity.
If I have everything at 12.00, I would blow myself out f the room with both channels on.
 
Well. The tone-control seems working like you wrote. Meanwhile I "resoldered" almost every joint. Didn’t change anything. I have an other inductor, not this one from tayda. (But is 100uH and 2A).
Should swapping tubes make a difference? One of them looks a little different inside, than the other …
Any other faulty component. (Which I dont believe - but I have no more ideas)
 
Anton K said:
Well. The tone-control seems working like you wrote. Meanwhile I "resoldered" almost every joint. Didn’t change anything. I have an other inductor, not this one from tayda. (But is 100uH and 2A).
Should swapping tubes make a difference? One of them looks a little different inside, than the other …
Any other faulty component. (Which I dont believe - but I have no more ideas)
Click to expand...
have you tried swapping the Tubes & see if you get a different reponse.
I only use JJ ECC83S.
 
yes, there is a slight difference. about 1db. In combination "A" gain is louder abd clean quiter, and in combination "B" there it is exactly the other way round. As written, about 1db.
I used this tubes.

I made a new audio, without any post-editing. I was foolish enough to have a compressor on the bus in the previous examples.
 
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… found out something. I have tried out a different power supply (9V, 500mA) and then the whole thing is much louder. Now I have to turn clean below 12 (about 10, as said). Dirt is still a little quiet (now I turn it to1 ). I think I can deal with it.

Now comes the weird part: I tried the "old" power supply (9V, 250mA), and as expected, volume is low. Then I switched back to the new power supply - and volume is quite es before! Next morning volume is loud again …
 
Anton K said:
… found out something. I have tried out a different power supply (9V, 500mA) and then the whole thing is much louder. Now I have to turn clean below 12 (about 10, as said). Dirt is still a little quiet (now I turn it to1 ). I think I can deal with it.

Now comes the weird part: I tried the "old" power supply (9V, 250mA), and as expected, volume is low. Then I switched back to the new power supply - and volume is quite es before! Next morning volume is loud again …
Click to expand...
Ah, that explains a bit. 250mA is not enough for Ambassador, 500mA is pretty much the minimum required. I typically recommend at least 600mA for dual-tube builds.
 
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