The Amp Garage

roberto wrote:The problem is not the layout, but how you built it.
We need picture of what you have done.

Agree, sounds like major ground issues as well
Need a gut shot to help you.

Hello All, I've seen schematics and worked on a few amps that have what appear to be clamping, or flyback diodes, either two or three 1N4007's in series from each of the OT primary windings to GND. It appears that the end result of the diodes is to keep the winding from going negative when the outp...

When it comes to inductors it can be much easier to use a gyrator IMO
Easier to create, no winding , if you have the supply options

The 465 is also a very fine instrument. A little bigger and heavier. Don't get any Tek scope newer than the 2465 series. They were the last with ordinary components inside. The newer ones have a lot of OEM parts that are pretty much unobtanium. Tek learned that it's more profitable to require facto...

You can deal with it on the probes but the multiplication factor of the probe doesn't = multiplying voltage handling capability. For instance mine is 150V with no probes and 350V with the 10x probes. There is a voltage rating on the probes. A 465B is a good choice for an older scope. I just treated...

All, I'd like to get an oscilloscope to be able to look at and see what is happening all along the signal path through an amp. I know that any scope will cover the frequency range of interest, but what about input voltage specs? What would you recommend for minimum max. voltages for AC and DC coupl...

You might want to put a series limiting resistor in Ah - the old split, split-load :lol: Yes, I was thinking about that too. I think I'll play with it a bit without a limiting resistor, just to see what the smallest value that I might want to use on the B+ side. Like with really hot humbuckers and ...

All, I would like to set up an adjustable split plate load. Using a potentiometer for this seems ideal. One side to B+, the other to the plate, and the wiper to the coupling cap. What I'm curious about is that I read somewhere that "...most POTS are not designed to be subjected to raw DC like this....

You have any meters?
Kind of tough to ID things with those pictures
At least tell us exactly what is written on them

I have a question for some educated ears and folks that know a bit about power scaling.. I like a level control before the phase inverter and I only scale the power tubes. Then turn down the level with the power scaling. Nothing else floated my boat except for this in feel and tone and I tried ever...

Just curious about why you want stereo in/stereo out in the first place? Are you going to use (a switch into) Two preamps => stereo dlator=>two poweramps? Yes its for a friend that needs to buffer two loops for two Seperate amps. Might want to think about iso transformers to avoid ground loops, loo...

Luthierwnc wrote:anyone?

You wont find a click less switch that is mechanical
Maybe Mosfet

I think I have discovered what has happened here though it will be a couple of days until I can check it out. An output tube swapping mistake appears to have allowed the full B+ of 400 volts to hit my cathode resistor and capacitor. The cap , which is rated at 160 volts could very well be responsib...

You really need to do an impedance plot. DC resistance is not very accurate and basically tells you if the coil is broken or the ballpark of the lowest impedance. Here is a VET 30 I just did an impedance curve on. The DCR read with probes 0'd out on a Fluke 87V is 6.8 ohms, as you can see the impeda...

Sorry to post twice in a row, but this is not related to the last thing I put up. I'm about to build a new amp. Last time, I made a mistake and installed an OT so the laminates were co-planar with the laminates in the PT. It didn't make any noise, so it wasn't a problem. But I'm wondering...is it s...