The Amp Garage

skyboltone wrote:Ok, so we won't pay any attention to anything other than the freeking amp ok!

Yes, I find it easier if I hold my hand over the top part of the picture, leaving only the knobs exposed.

Cool I didn't know radios counted I got radios I was looking for a radio cabinet to make an amplifier for the MP3 player. And have the look of an old radio. Turns out, it was a great old radio with a phono input. All I had to do was build the pre-amp, after I found out that the radio/amp worked. So...

1946 Westinghouse H-130 AM Radio: [IMG:800:600]http://i132.photobucket.com/albums/q32/Jack_Hester/RadioandPre-amp_zpsec69c614.jpg[/img] This is on my bench at work. Replaced the decoupling capacitors and the radio works great. Didn't know that so many AM stations still existed. Fabricated a pre-amp ...

Way back in the mid 70's they told me the transistor would replace all tube devices... That's the same thing they told me in electronics school (early 70's). That is, the head of the department said that he was told to give us the this speach. Then, he said off the record that tubes would never die...

On your next Champion retro, try: 6CA4 9-pin full-wave rectifier 6X4 7-pin full-wave rectifier 6X5 8-pin full-wave rectifier Each of these has a 6.3v filament, and each should be enough to power a nice single-ended amp such as this one. Just an alternative to the solid-state diode route. Jack

What I want to do is fit in a small isolation transformer, de-stink and re-cover the box in purple tolex, and build as high-gain an amp as possible with this ridiculous bunch of tubes. Loctal tubes appear to be dirt cheap, so I've got no particular issues swapping in different ones if these are tot...

Ok, new power transformer and new diodes and she is singing. It, however, is only clean at 1 anything more is very distorted. Any ideas? Sounds like a peppy little amp. You can try this little gain mod (actally, an attenuator) and see if it does the trick: http://www.turretboards.com/vjr/valvejr_la...

Google put up this warning when I went to check out the "Marshall" schematic: Paranoia or what. Steve - Not paranoia. Just being safe, is a better term. My files are automatically scanned by my PC-Tools anti-virus software. I've run into this before, but never the same circumstances. I have sent my...

Love, kindness, and compassion got me through this difficult time. I guess when you're thinking more about others than yourself, it's easier to avoid the destructive self-pity. Man, you got the best of attitudes! The last part I'm afraid would be the part to overwhelm me, if I encountered what you ...

David - Your pre-amp tube appears to be just like a 12AX7, except your 6.3v filament wiring attaches to pins 4 & 5. On the 12AX7, 12AT7, 12AU7, 12DW7, etc., pins 4 & 5 are connected together, and one lead of the filament wiring goes to one of these pins. The other filament lead goes to pin 9. Other ...

Also pulled the diodes and found the problem. David - What kind of problem did you find with the diodes? I was looking over the schematic. Nice, simple little amp. Do you already have the tubes that it calls for? If not, that configuration is very easy to convert over to use a 12AX7 and 6V6. The la...

Looking at the photos, I see quite a bit of cleanup and lead dress needs to be done, before going too much farther. The signal ground end of your decoupling caps have individual green leads coming from them. Jumper each of these together (top or bottom of the board) and carry only one lead to wherev...

When I powered it up the power transformer started smoking. David - You may have heard others ask, in other threads, but I'll ask it here: Do you have a lamp limiter that you can bring the amp up on? Saves a whole lot of headache, when troubleshooting a new build. If you don't have one, make that y...

Okay, so I need to be looking for a bum ground then? Not necessarily. Just one thing to look for. Mine happened to be a missing one. I put mine aside for several months, and worked on other projects. When I came back to it, and traced it again, from the layout, I knew that I had it built like the d...

Can you post the schematic or at least the part with the missing ground? When I get home this evening, I'll find them and print to a pdf file. Not fancy schematics, but they help with troubleshooting. As to the missing ground, I did not mark up the schematic to reflect which one it was. I just drew...