The Amp Garage

Stevem,

According to your tolerance figures, I'm within a reasonable amount of voltage drop. I just wanted to make sure since it seemed a bit lower than what I am used to.

Best,

Phil D. (pjd3)

Hey Stevem,

Yes, the PT is 660vac across the coil and specs 130mA.

The model is found on the "Products" tab, the 2nd entree from the very bottom of the page.

Thank you,

Phil D

HI johnny,

It is the PT330Mi and I did use both primaries, wiring it up as diagramed for 120vac operation.

Best,

Phil Donovan

Hello, I was hoping for a quick sanity check here. Thanks, This is my first diode rectification tube amp. I have Musical Power Supplies PT @ 330-0-55-330vac and a pair of JJ 6V6's Push-pull. Unloaded, I was seeing about 467vdc at the first filter cap. Following the full set of tubes put in (3 12ax7s...

Ha! If "dummie" was in the Webster dictionary, you would see a photo of me with DMM probes inside an amp chassis. I was referencing ground and not the signal wire. That was a bit embarrassing as I know that wouldn't work. But, all is well now, and happy to say that I won the 50% chance game, and the...

I will likely go do this test tonight making sure I ground the centertap.

I just didn't see that in the drawing first time around.

Thanks,

Best,
PJD3

Oh for Geezis sake, I discovered the whoa's of my ways. After enlarging the diagram I noticed that for this OT phase test the primary center tap needs to be grounded. I missed that and likely the reason why I was getting 7.2 volts on both ends of the coil. We should be good now. Thank you, Best, Phi...

Thank you for posting this. I tried this over the weekend just to do it and see how it works. I knew I must have been doing something wrong because I measured the same voltage on each side of the OT primary. I bet I was using the wrong grounding and one of my speaker jacks is a shorting jack. Althou...

Hi Martin,

Yes, I had planned to make that the very first test I do tonight, and the tenet of that test makes alot of sense - just another method for showing the relevant conditions of OT status!

Thank you,
Best,
Phil D.

Thanks everyone for inputting on this. While I was initially ready to go forward with simply doing the "50-50" chance approach, I did make an intentional decision to see this through in an analytical approach, just to challenge my little brain and expand my understanding of what is really happening ...

Hello, So, while I get that it is totally feasible to spark up the new amp build (Sluckey's 6V6 plexi - two in one chassis stereo amp) and have a 50% chance of being correct on which OT wire, blue and brown goes to which power tube so that the NFB ends up being just that, negative feedback, the alte...

Hey nuke,

Just to mention, I've been receiving the same "too many requests" message as well, and not given access to the website.

Best

Phil D

Thanks guys, for info and images. I find these cabs kinda interesting, and something in me resonates with them that they may be a worthy idea specifically for the application I would be using them6t0 in. Does anyone have any knowledge of an Altered Mesa Boogie Thiele cabinet that has been calculated...

Correction, I was calling the EV 15L the EV12L by accident in the above post - fixed it!

After doing some research today, The prospect of using an EVM 15L with a TS606 is looking like a good possibility. It's compatible with that cab, and the frequency tuning seems to be in a good place. The EVM 15L has a freq range of 50Hz to 5K which is OK for what I'm doing. I did intend on having an...