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Heeeeeeeeeeeeelp MyTC15
You name it has happened to my build.
Starting up no sound, filaments on the rectifier tube and output tubes light up, no snap crackle or pop, no smoke, smell or excessive heat.
Checked speaker and Cable with another amp A-OK
Checked Cable to input jacks A-OK
Heater wire 6.3 VAC, did not check B+, check V4 and V5 both pin3=7 , pin7 =365 -7 or something?
V1 pin1=143, pin 3=1.34, pin6= 144, pin 8=1.348
V7 Amperex EF 86 = Pin1 77.0, Pin3 1.9, Pin6 115, can’t remember pin 7.
Filaments on V2 and V3 went out, no heat coming off of tubes, brand new Sovtek 12ax7 down the tubes, pun intended
Took amp apart, check jumpers under board, bad jumper, no continuity, and rewired and soldered all.
Took wires off of tube sockets and soldered all and checked continuity, replace all12ax7 with Masa 12ax7a
Turn on Amp, constant hum, checked all grounds tighten all stars grounds, replaced all shield cable. Took all tubes out one at a time except V6 still had hum
Audible snap and sound level when switching crunch munch switch, audible sound level when turning VMR it worked I think. , No sound level change when turning volume knobs.
Turn off Amp and went out and had a lot of beers.
Next day sobered up and took some reading on the amp

HVAC 118, B+ 322/304, All heater 6.2
V1 P1=144, P3=134, P6=144, P8=13.48
V2 P1=252
V3 P1=267 Way too hot
V4 P3=13.1, P7=307
V5 P3=13.1, P7=304
V6 P2=112, P4=290, P6=296, P8=112
V7 P177.0 P3=1.8 P6=115
PT red wire to p4 and 6 V6 =304V
I have lost my Amp guy who was suppose to help me and have shut everything down because the numbers look too hot and I didn’t want to burn anything up. When I did get sound (hum),I didn’t do anything it just started to hum.
Oh, Caps all 5 450V =23.7 from left to right
220uf 50V=.10k
22uf 50V=1.52
22uf 50V=1.53
22uf 50V=2.29 Hope I’m reading my meter right
Thank you all for any help you can give me, I don’t have a camera to post pictures
The best to all of you
Dave from Portland Oregon
Just started up my TC15 again No hum, no sound
Question:
On V2 is there a jumper between pin 3and pin 2?
Saw the pictures of Stephen's Tone contour where there look’s like
a jumper from pin 1 to pin 7, does the wire go from pin 1or 7 to330k on the board?
Thank you

_________________
Love is a small Cat on your amp purring as you play

Just to be sure, as this confused me at first, V1 is the first 12ax7 not the EF86 (the EF86 is V7).

Pins 3 and 2 on V2 are NOT connected. There is a jumper from pin 1 to pin 7 however, there is NO connection from pins 1 and 7 to the board. They are connected by a 100k resistor to pin 6 of V2.

Is V1 pin 3 134vdc or 1.34vdc?

Pins 2 and 8 of the rectifier seem wierd to me. Is this with or without tubes? Standby on or off?

I would suggest removing the VRM from the circuit untill everything else is fixed.

If you can, borrow a camera pics can help a LOT!

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Deric®

Thanks Deric for your reply, I should have just give the last part of where the amp stands as too much info can be confusing.
I will say, before I got sound and the tubes were working most of the numbers were in the ball-park if not low.

Just to be sure, as this confused me at first, V1 is the first 12ax7 not the EF86 (the EF86 is V7).
Yes
Pins 3 and 2 on V2 are NOT connected. There is a jumper from pin 1 to pin 7 however, there is NO connection from pins 1 and 7 to the board. They are connected by a 100k resistor to pin 6 of V2.
THANK YOU, YES, I HAVE CHANGE IT.

Is V1 pin 3 134vdc or 1.34vdc?
1.34 I CAN’T TYPE FORGOT THE DOT.

Pins 2 and 8 of the rectifier seem wierd to me. Is this with or without tubes? Standby on or off?
STANDBY IS off, TUBES IN, SEAMS TO HOT TO ME

I would suggest removing the VRM from the circuit untill everything else is fixed.
I WILL REMOVE VRM BUT IT DID SEEM TO WORK WHEN THE AMP WAS HUMMING AS THEIR WAS NOTISABLE SCALLING OF SOUND OR VOLUME WHEN AMP WAS HUMMING.
Thank you again
Dave
[/u]

_________________
Love is a small Cat on your amp purring as you play

With no tubes in and standby ON, what is your B+ voltage at the first filter cap (where the standby connects to the cap-can) with the VRM control set to max? Set to minimum?

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Deric®

Dear Deric
I’m so new at this that I’m well past my pay grade. Any help will have to be in the simplest terms to me like, set meter to Vdc or uADC or what ever. Again thanks for taking the time. I think I see where we are going, is my B+ can caput.
I measured from both the B+ can and the 22uf 450V Caps; it took at least ½ hr to reach .297 VDC, VRM pot turned clockwise and .218 VDC counter clockwise About 15 min.
Looking into my amp from the back my wire routing is V6 pin8 to standby, from standby to right lug of 1mag VRM pot, to VRM board, from VRM board to left side of B+ Can. The measurements could still be going up or down with more time I didn’t wait.
I think I can barrow a digital camera to post some picture.
Thanks
Dave

_________________
Love is a small Cat on your amp purring as you play

All power supply measurements after the rectifier (V6) are vdc. Set your DMM to vdc and put the red probe on the point to be tested and the black probe on a good chassis ground point.

Sounds like you need to disconnect the VRM before you do anything else. Those funky voltages could be a VRM issue. It should not take more than a few seconds for a cap to charge up and stabilize.

FWIW, I wire mine in this order (not sure if it really matters):

V6(Rectifier) - VRM - Standby - Cap-can....

Pics would help VERY much.

Hang in there....

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Deric®

Hi Deric
Will I have303 Vac From V6 No tubes.
Removed VRM
B+ climbing slowly to .132Vdc after 20 min still going up standby both on and off test
Is this a bad B+ can? Wire rout, V6 pin 8 to standby to left side B+
Dave

_________________
Love is a small Cat on your amp purring as you play

Can you back up to this and give us the step by step results? Just to be sure the thing has correct power etc.

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

Hi Stephen
Sorry but I don’t know what is not clear in my post, Maybe I’m not setting dmm right.
I have soldered all, and have found mistakes (cold solder under board) no jumper on V3 pin 3 to 8, re-jumper all tube sockets that needed it, replaced all shield cables, check and tighten all star grounds, heaters read 6.3 all tube, have 303V coming from red wires off of PT and disconnected VRM and routed wired from V6 pin 8 to standby to left side B+. There are no tubes in the sockets.
I know I must be doing something wrong but theirs growth through adversity and It may not look it but I’m learning a lot and hair has changed from gray to white
Dave

_________________
Love is a small Cat on your amp purring as you play

Ok, with all the tubes out, set DMM to VAC, measure between pin 4 & 6 on rhe rectifier, V6.

If it's around 580 VAC good. Measure the AC voltage between pin 2 - 8 . 5 VAC?

IF this is all goo, plug in the rectifier tube. Turn it back on. Standby off. Set DMM to DCV and measure from pin 8 of V6 to chassis? What is VDC? Turn it off.

Check that the can cap is wired correctly. For example, that you have the 1.5K power resistor across the correct lugs, and B+ lead to one of thoose lugs. IF it's good, turn it one, let V6 warm up, flip standby. Now measure the VDC at the point where the standby wire connects to the can cap. What is that voltage?

I just want to establish the power is set up corectly and we can go from there.

Pics will be necessary very soon.

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

Thanks Stephen
measure between pin 4 & 6 on the rectifier, V6 is 611 VAC
AC voltage between pin 2 and 8 is 1. (Point one VAC)
Yellow wire on pin 2, white and yellow wire on pin 8.
pin 8 of V6 to chassis? Around 317 VDC Standby off,(would have no sound)
where the standby wire connects to the can cap standby is on(would have sound) 419 VDC,
Thank you
Dave

_________________
Love is a small Cat on your amp purring as you play

You should have 5 VAC between pin 2-8, and you should have around 420VDC STANDBY ON at the can cap, with no tubes installed except rectifier.

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

This is more clear
Ok, with all the tubes out, set DMM to VAC, measure between pin 4 & 6 on the rectifier, V6.
If it's around 580 VAC good.
between pin 4 & 6 on the rectifier, is 611 VAC

Measure the AC voltage between pin 2 - 8 . 5 VAC?
AC voltage between pin 2 and 8 is 1. VAC
Black probe to chassis pin2 Yellow wire .432.
Black probe to chassis pin8 white@Yellow wire 1.

IF this is all good, plug in the rectifier tube. Turn it back on. Standby off. Set DMM to DCV and measure from pin 8 of V6 to chassis? What is VDC?
pin 8 of V6 to chassis? Around 313 VDC Standby off

installed tube, let V6 warm up, flip standby. Now measure the VDC at the point where the standby wire connects to the can cap. What is that voltage?
Standby wire connects to the can cap standby is on 419 VDC


Thank you
Dave

_________________
Love is a small Cat on your amp purring as you play

So the good news is that the B+ with no tubes installed is correct!

Now, you should have cheked, double checked your connections to tubes, controls and the board build. etc. Also before you power up, you must ensure you have a speaker connected to the amp. Always to this when you have power tubes installed and amps turned on.

Have you checked everything? Go over the layout with fine tooth comb crossing off your connections.

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

Hey Dave.

Do you know how to use your continuity tester on your multimeter? That can tell you if you have a decent connection between two points.

Touch one probe to the control or cap, or resistor, etc. (not the wire) that the wire being tested is connected to, and the other to the corresponding component on the other end of the wire . Mine beeps when there is electrical continuity. Make sure you don't just touch the opposite ends of the wire, that won't detect if the solder joint is bad.

For example, if I am checking a connection between a volume pot and a board component, I'll touch the probe to the pot's terminal below the solder and on the lead of the component of the board, that'll tell me that the solder joints between the points I'm touching is good.

Hope that helps a bit.

J.

J you are psychic that was my next Question to post.
People on this forum are asum
Thanks again
Dave
PS OH thank you, thank you, thank you, Ifound some bad stuff.

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Love is a small Cat on your amp purring as you play