Tube Amp Archive

I've found out that the power transformer only performs at spec if it meets its expected load, 42mA. It has a linear response between 0-42mA.

How do I add to the load in the circuit? dang!

How does an amp builder decide on the ideal power supply and rectifier? I have a single-ended 8ohm 6V6 design. Designed plate voltage is around 315-350V? My design, which I believe is flawed, uses a 250V secondary (CT not used), bridge rectifier, and 150uf/350 for the output transformer > plate (pin...

Booya, thanks.
Perfect site for explaining oddball ceramic discs!

I'm having trouble ID'ing these two caps. They're found in a Champ-type single 6V6 amp. 1) 2200M UW AUW 1.4KV This cap is connected to ground and between the Plate of a 6V6 and output transformer. 2) 300K Z5P 3KV This cap is connected to ground and the plate of a 12AX7. The circuit calls for 225VAC ...

From what I can tell they are all open style designs and it was recommended that I need closed housings to eliminate the chance of introducing hum.

Do I up the input volume - say to 1M?

So I have another Herzog here, 1 thousand off the serial number of the first model I used. This one only has one power transformer and a mult-section FP type cap. Details to follow. One of my intentions with this preamp is to use it as a Leslie preamp. However, I tried the herzog today and it is not...

Thank you, things are definitely getting clearer. So since I don't want to start changing up the rectifier maybe I'll just stick with buying two filament transformers. How many amps should these be rated for? Does it matter if I get an open body transformer instead of an enclosed version? 6.3V @ 4am...

Any issues I should be aware of when adding center taps to the circuit? I've measured the input on the rectifier and the 2nd transformer is indeed the same but reversed from the 1st one. 116VAC! Why do I need a champ replacement then, which can pump out 300+ VAC? My drawing skills are very very crud...

Hey Martin - thanks for the info. I suppose this reduces the costs associated with building the amp as I only need to find rather simple filament transformers 120V > 6.3V. Where is the cheapest place to get transformers? (both power and output. I've been looking at Digikey and Mouser). Is there way ...

Ahoy, I'm trying to copy a friend's Serial 38xxx RB's herzog. It does not match up with the schematics. I've got everything down except i'm unsure of which type of transformers to source. I know this is similar to a champ, but what I hold before me is a bit of a puzzle. There are 2 power section tra...