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Finished my Deluxe. It's the first amp I've ever built. Fired it up, all the tubes are getting hot, no weird noises, but it doesn't get loud. It sounds quieter than a 1/2 watt amp.

All controls and inputs work properly, and all the tubes are glowing up nicely, but it sounds like it's all preamp volume with nothing from the power amp.

I'm sure the first question will be about checking voltages. Can one of you outline the safe way to check. (black to x, red to y, set DMM to). I've never done it before and don't want to just poke around until i get it right.

Thanks,
James aka LowWatt

Can anyone see what I may have done wrong? Here are some pics :

The easiest way to check voltages is to clip the negative lead (Black) to the chassis, then use the positive (Red) to probe carefully. Since all the leads go to the board, the safest way is to measure the voltage right at the eyelet on the board where the lead to the tube is connectged. Record the voltages on the layout and compare them later to the documented voltages.

Let us know what they are.

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

Thanks Coco. Using an NOS 5Y3, here are my voltages with the recommended number in brackets :

12ay7 (v1)
Pin 1 - 117.5 (120)
Pin 3 - 1.8 (2.0)
Pin 6 - 116.4 (123)
Pin 8 - 1.8 (2.0)

12ax7 (v2)
Pin 1 - 149.5 (167)
Pin 3 - 1.1 (1.1)
Pin 6 - 183.8 (175)
Pin 8 - 42.3 (70.5)

6v6 (v3)
Pin 3 - 341 (380)
Pin 4 - 320 (338)
Pin 8 - 22 (20.4)

6v6 (v3)
Pin 3 - 342 (382)
Pin 4 - 319 (339)
Pin 8 - 22 (20.4)

Pin 8 on the 12ax7 is definitely the biggest issue.

Measure the resistors around v2 and confirm they are correct. B+ should be around 400 with a new 5Y3. What is yours?

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

Thanks Stephen. I'm using an NOS Phillips rectifier and getting 329 volts measuring at pin 8 of the rectifier. (marking on the layout for B+) With the Sovtek that came with the kit I'm getting 392v.

Also I've triple checked every resistor, by eye and with a DMM. I just finished going component by component and marking off the entire board, also comparing it to other board pics I found on the forum. I then went pin by pin through every tube and verified that each tube is wired correctly.

I've gone over the schematic several times marking off every connection and I think my wiring is right. The only thing I'm thinking may have been the problem is that at one point I touched up the solder connections at the 2x 220k resistors (above the 56k resistor) that connect to a wire running underneath the board to pin 6 of each of the 6V6s.

I did this with the board already attached in the chassis. If I didn't have a good enough mechanical connection, maybe the underlying wire fell. Is there any chance that is what is leading to the issue? I'm getting 0volts checking at those points. Should I be getting any?

Really it appears the preamp is working 100% :
- volume/tone controls work (interactive nature is definitely noticable)
- at 6 on the volume, I can just start to hear the amp very faintly and cleanly
- at all on 12 there is just a tiny bit of light preamp tube sounding overdrive and a bit more volume, but still very quiet. If I switch v1 with a 12ax7 I get more grit.

All the voltages seem to be coming in at or near spec (at least enough that it should sound louder than connecting a preamp to a speaker. I assume the issue has to be somewhere where the preamp audio signal is meant to flow into the power amp.

I really don't know enough about electronics to speculate, but I know enough about tube audio to say it really does sound like the preamp is running straight to the speaker.

You can test the continuity frm the components lead to the pin on the tube, for example, to see if it is still connected.

I would go over the connections and do this for each one, testing continuity against the layout.

Do you have any spare tubes? A 12AX7 will work in both V1 & V2. For a test anyway.

Also check the connections to, at and between the power tubes.

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

I've got spares for everything except the 6V6s. I'll test the continuity tonight when I get home from work and report back.

Thanks for all the help Stephen. Problem solved. The amp sounds amazing!!! I'm really kicking myself for not taking a digital shot of the underside of the board before mounting it in the chassis.

After doing a continuity test, I realized that I was missing the wire that connects the .02uF capacitor to the 1M resistor. I had mined the forum for build photos that I used along with your materials for reference and unfortunately I followed this one from ajcoholic http://acapella.harmony-central.com/for ... stcount=38 a little too closely and missed the same wire he did.

I've attatched the wire neatly on the top of my board and the amp sounds perfect. No hum or weird noises, great tone. All that's left for me to do is build the speaker cord and attach the chassis to the Red Fang in the combo. I've been using the ceramic Tone Tubby in my m@z Jr. so far for testing (which sounds awesome with the Deluxe BTW).

Thanks again for all the help. I'm really proud of how good this thing sounds.

James aka LowWatt

Hey, hey, hey! Alls Well that Ends Well.

Now you know to follow the layout instructions! nono . Some people actually put the wires on top so they always know they made the connection. Glad it's working to your satisfaction.

Now, an Alnico Tone Tubby is just the thang ....

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

Yep, I still can't believe I made that mistake. I was using the layout as a bible and the photos for reference, but somehow my eyes went past it. I'm pretty sure the other thread even mentions the missing wire in the play-by-play too. Definitely not taking a pot shot at him there. It was my mistake and It was looking through his thread that gave me the confidence to start this kit and gain a good understanding of how it all comes together before putting out my cash.

I've been playing the Deluxe for the last 2 hours and I've got to say, the Red Fang is a pretty nice match. It definitely brings out a chimier side to the Deluxe and it's so efficient (103db I think) that I should be able to stay loud and somewhat clean with my band. I guess I'll find out for sure at practice Thursday.

Now I'm eyeballing that TC-15 kit...

Mr. Coholic is a very fast and good builder. I think 5 Trinity Amps so far?!

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

Which rectifier are you using? The tonal difference will be very noticeable between NOS & new.

What were the final voltages btw and can you update them?

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

I'm using an NOS Phillips 5Y3. I didn't have the Sovtek in there too long, but it did sound a little more strident, firmer, and a tiny bit harsh in comparison with the Phillips.

I'm off to the retirement home tonight to share a Guinness with a retired trumpet player, but when I'm back at home tomorrow night I'll check the voltages again and toss them up for the record.

2 deluxe's
2 TC 15's
1 sIII
1 original 15 watter

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6 total...

Sorry about that missed jumper, I did indeed put that one on the top. If I remember I missed it but found it missing after I had mounted the board, and then just soldered it on the top. I never thought someone would use my photo for their layout! Or maybe I was trying to keep you on your toes..

Hey Stephen, youre going to get to listen to my sweet TC15 this weekend... I just hope you can stand the vocals (I have been fighting a cold for two weeks which certainly doesnt help!)

AJC

6 - I stand corrected!! and you got the T shirt to prove it!!

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

Haha. Well it definitely worked. I found it easier to see the back of the board than to try to visualize everything flipped over from the layout.

The thing is, I got into this to learn how an amp comes together and to improve my almost non-existent electronics knowledge. Without making that mistake, I probably would have never learned how to check the voltages on my amp and do even basic things like a continuity test. Things that I now see as absolute musts to know.

Thanks again, it really was your thread that helped me see that I could do it and that was the final push in getting my money to Stephen's hands.

I know this stuff is not for everyone (my co-guitarist who tried in vain to assemble his TC 15 proved that) but I bet a LOT of guys could indeed do it and do it well.

I think the key is patience and an understanding to take things step at a time.

AJC

Using an NOS 5Y3, here are my final voltages with the recommended number in brackets :


12ay7 (v1)
Pin 1 - 120.1 (120)
Pin 3 - 1.9 (2.0)
Pin 6 - 118.4 (123)
Pin 8 - 1.9 (2.0)

12ax7 (v2)
Pin 1 - 151.5 (167)
Pin 3 - 1.2 (1.1)
Pin 6 - 187.4 (175)
Pin 8 - 43.7 (70.5)

6v6 (v3)
Pin 3 - 349 (380)
Pin 4 - 328 (338)
Pin 8 - 20.8 (22)

6v6 (v3)
Pin 3 - 350 (382)
Pin 4 - 329 (339)
Pin 8 - 20.8 (22)