The Amp Garage

I just bought this Mercury 045RS-L output tranny. Paul pretty much talked me into it over the tweed bassman. Im putting together parts for an ODS.

I assume the 6.6K primarys for a pair of 6L6 output tubes. Anyone using this transformer?

Sure could use some thoughts here.

Thanks
Dan

We are talking about 40VAC? Yealds 56VDC for bias maybe a bit more? I have a scheme I worked out years ago for regulated screen supply on transmitter modulators. Really cleans up vocal audio. You could get your supply off of B+ that way. It's just a zener diode string driving a fat high voltage Darl...

You can carefully take the old one apart and replace the innards with new electrolytic caps. The new ones are much smaller than the old and will usually fit. I have done this many times with a small hack saw or even a sharp blade (how about a plumbers tubing cutter) then put it back together with he...

Take it slow David. No tubes, then add the rectifier tube, then add the pre tubes, then add the power tubes and Phase Inverter. All of this with no signal. Check voltages, plate, cathodes, heaters, each stage of the power supply. It's likely that you will have variations in the expected voltage at B...

If you ain't a tech, then become a tech. If you can't become a tech, then rely on your tech. Seems reasonable to me. Shorted filter caps will do precisely the same thing that you describe but usually rather spectacularly. In the smoke department. If you can smarten up enough to cut the power tranny ...

Congratulations Mister:
I love to scrounge too. We used to find old tube amps all over the place but no more. I keep waiting for the garage sale McIntosh 275 in mint condition. Rip that baby up and make two guitar amps!! Just kidding.

Good job.

Dan

Well, that's a good question. Even if you've been doing this stuff for a long time you never feel absolutely certain about throwing a switch the first time. Especially on high power tube circuits. I use a Variac and bring it up slow the first time. A variac is a variable transformer that you can dia...

Well, I have it all wired up, and turned it on.....and I DIDN'T DIE! :) That right there is a success. On top of that, the voltages all measured out correctly, the recto tube heated up nicely, and all the swtiches seem to be functioning normally. However, I did notice that when I have the amp on st...

I just picked up a couple of these trannys off E-bay. One is supposedly burnt up due to a shorted tube, the other is fine. Anyone have direct experience with these transformers for guitar amp work? There is a fair amount of iron there. I may have someone rewind the dead one with 50 Watt capacity win...

I think there must be some at least minor science out there for open backs. Dumble gave me strict dimensions for the cabinet and the hole in the back when he built my amp. I built the cabinet of course. He called for a lumber core box and a couple of 6" +/- circles some distance which I don't recall...

Greetings Lads and Laddies: I've been using the registered version of Boxplot 3 for some time but it doesn't address open back cabinets or even single driver boxes very well. Are any of you familiar with box modeling software that is usefull to those of us here that build amps and boxes? Thanks in a...

Krash I agree and that's why I was trying to get a clarification on what it was he was trying to do. There are a lot of off the shelf ss headphone guitar amps out there. I don't recall seeing a tube one. After reading Bob-I's response I thought he was asking how to modify an amp to get some kind of...

Hi Everybody...I've decided to assemble an ODS board and find there are so many drawings, pictures and all yet there seems to be some question as to which of them are correct! I gotta tell ya I'm really flying by the seat of my pants on this one so if anyone has an idea as to which one or two might...

Gut the bastard.... I had the G100T. Looked the same!! Worst amp ever. Nasty tones and unreliable. Gut it! LOL Well, I wasn't planning on destroying it, just making it something more useful :-). But I suppose I could pull the chassis and hang on to it in case the amp ever becomes valuable on the vi...

Hi Lefty: Tube sockets available from Tubesandmore.com. Iron from Mercury. I just can't see destroying an amp for a couple hundred. If you're in any kind of tax bracket at all, you can donate that to Salvation Army and get full credit off your income. Or just give the darn thing away to some promisi...