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RULE # 1 - NEVER operate a tube amp without a load.

I hope it stodd up to the abuse.

The rest looks good !

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

Yeah, I thought so. Maybe you should add that to the instructions for dummies like me.

It's in the Power Up section, but I guess it's not obvious enough.

Is it still working now, with a load connected?

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

Some DO NOTS

• Never, never, never run the amp without a speaker plugged in. This can cause major damage.

• Do not flip the power switch off, and then back on rapidly. This can cause power supply damage.

• Never replace a burned out fuse with a bigger-amperage one. Remember - there was a reason the first one burned out, usually protecting something more expensive. Putting a bigger fuse in will just ratchet up the power level until something really vital burns out. If the second equal-rating fuse pops, turn it off and get a tech to look at it.

• Never ignore signs of high heat inside - a wisp of smoke or a burning smell is NOT normal.

• Your amp produces lots of heat, and will continue to do so even if you block the fresh air vents. Blocking the vents will overheat the amp and you may have to get some very expensive repairs done.

• Never ignore a red glow other than the small orange ends of the filaments. A red glow over a large part of the internal plates of the output tubes means they're about to melt. If you notice this, shut it down and get a tech to help you find out what it wrong.

Some DOs

Add another speaker into the "external speaker" jack; a mismatched speaker load won't kill it, while an open circuit (disconnected speakers) may do so.

Overdrive the stuffing out of it. Tubes are very forgiving of massive overdrives, unlike solid state stuff. As long as they tubes don't overheat or stay overdriven for long periods, it's not fatal.

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

I'll try it again tonight.

While we're on the subject, how should I turn it on and off? Should I let it warm up or cool down in standby? Or is standby just for when you won't be using it for a while?

To turn the amp on, flip the standby switch to standby, and then turn the power switch on. Leave it this way for 30-60 seconds, and then turn it to normal operation. This gets the heaters hot before the main power supply comes up.

To turn it off, simply flip the power switch to "off", don't use standby. This lets the still-conducting tubes bring down the high voltages in the power supply.

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

B+ is 349V. I'm going to connect it to a speaker now....

...well, faint sound on the TMB channel, and no sound from the 18W channel. Here's an update on my voltages:

B+= 349
Heaters= 6.5 (pin to pin)

*V1*
1= 151
3= .86
6= 152
8= .83

*V2*
1= 160
3= 1.32
6= 252
8= 159

*V3*
1= 207
2= 45
3= 63.5
6= 202
7= 44
8= 63

*V4*
3= 8.9
7= 322
9= 308

*V5*
3= 8.8
7= 316
9= 308

They're all low, but in the ballpark. Anything look off to you? Thanks again.

I don't quite understand, have you been running the amp without a speaker or other load connected? If you have it's not beyond the realms that you have fried the OT.

I ran it without a load for about 5-10 minutes. So yeah, I might have to replace the output transformer. Tonight I built an 8 ohm load to use during testing. It's my first amp project, if you couldn't tell.

That's a bit sad. I have never been a great fan of dummy loads, I prefer to use an old 8 Ohm speaker as it gives you the opportunity to solve hum, motorboating, crackling issues as well. I have a rough speaker cabinet with a dispensable speaker in it on my bench for this purpose. Until you are sure of your OT status you are not going to get much further, your voltages are in the ballpark as you say so the next thing would be to get her singing.
Good Luck
Nigel

Voltages look respectable but the voltages at V4,5 do seem low, compared to your B+ (which is right on). This could be due in part of the OT problem because they are connected to the OT primary.

OT Doesn't sound great.

Fully Disconnect the OT primaries & secondaries and measure the resistance on the primary from each side. Measure the reistance on the secondary from common to each lead. Note all the values. If any are zero, it's toast.

More extensive OT testing can be found at Guitaramplifiermagazine.com

http://www.guitaramplifiermagazine.com/ ... chtip.html

If it all proves to be bad, I have single OTs here in and will help get you going.

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

I'll check it tonight. Hiss goes up as I turn up the volume, would this happen if the transformer was bad?

Who brought the marmalaide? Because we got toast. 0 ohms between any of the secondaries. Kids, let this be a lesson to you.

I guess I'll be contacting you about another output transformer. At least it wasn't an expensive part that I smoked.

What was the resistance on the primary from each side?

I'mm gonna measure a brand new one for reference and post it

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

It was around 610 ohms from end to end and maybe 300 from middle to end on the primary side. From any of the secondary wires to any of the others it was 0 ohms.

I'm less bummed about the money than the wait to get the replacement.

Appprox 300 on either side of the primary center tap?

I"ll measure a new one later on. Watch this space for an update..

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

Output Transformer Resistances:

286 ohm - brown to CT on primary; 339 blue to CT on primary

On secondary approx 10 ohm from each tap to black (common)

Looks like the secondary is fried.

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

Hey Synthetic

I'm a first-timer right there with you. Don't give up hope. It's really very exciting to see it through. It will happen.

Help is in the mail - EXPRESS!

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