The Amp Garage

My scope is a 1950's era Heathkit that I rebuilt. Straight lines is all I can do at the moment. Given that it would also be a hand-built differential amplifier (e.g. "best" op amp I can find in my parts box with 1% resistors and trimmer pots to zero stuff out during calibration), and that the eye is...

You don't need to dive into "did you remember the sound right" - there's +/- 20% variability in value on the caps in two otherwise identical builds, and probably different tubes. There are guaranteed audible, explainable differences, I don't know why anyone would decide wires were the cause. Was goi...

Wow, for a minute there I thought I could hear the difference between things like PVC and Teflon wire and different resistors. Thanks to the wonders of science I realize I am delusional and not in touch reality. Or, instead of sarcasm, you could slap science back in everyone's face by running some ...

BTW if anyone cares to really learn the math I recommend the book High Speed Digital Design by Howard Johnson. https://www.amazon.com/High-Speed-Digital-Design-Handbook/dp/0133957241/ref=sr_1_1?ie=UTF8&qid=1536953887&sr=8-1&keywords=high+speed+digital+design It's $100, and despite being subtitled "A...

At audio frequencies stranded vs solid vs dielectric strength of insulation isn't going to matter. Be thick enough for the current and call it good. I prefer stranded because it's more flexible, and PVC insulation because Teflon gives me a headache when it heats up during soldering. ("isn't going to...

If the two channels are completely separate and switched at the output, why not get rid of the input relay entirely? Just run the input to both grids simultaneously

I don't think it would help design a detuned cab - the working theory behind the detuned cabs is "hey this sounds good!" - there's been no real mathematical analysis of any of the principles behind it that I'm aware of. BTW, I built a detuned 2x12, had to modify Kevin's plans to make the ports bigge...

I use a circuit like this:

http://www.pcbheaven.com/userpages/LED_ ... orklog&p=3

I use high voltage parts, and I connect it to a 5v zener diode instead of directly to ground, so it'll turn off when it hits 5v or so (which is low enough for my taste)

Pat

Phil - that looks like it might work. I'll order 'em up and give them a try. I never searched with metric values and missed them...

SoulFetish - I'll PM you if the mouser potentiometers don't work out.

Thanks everyone,

Pat

Hi everyone, I am back working on my Zenith radio amp project (won't bother linking to the other thread, no photos are visible because Photobucket changed their terms), total redesign and had some PCB's made and it's under construction. I need a two dual 1M audio pots. I also want to reuse the origi...

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I don't think you have to worry about symmetric vs asymmetric clipping, the return signal from the FX loop is small. The FX loop works with the clean channel too, so the recovery stage shouldn't be generating any kind of clipping. Check this thread out: http://www.thegearpage.net/board/index.php?thr...

There's a whole forum dedicated to the SLO-100 and high-gain amps in general, you'll get definitive answers there: http://www.slocloneforums.com It will change the tone, you'll end up removing one recovery stage and DC-coupled cathode follower. That just makes it different, not necessarily better or...

Structo wrote:So the $20 scope cost $400 to fix?

Just kidding, I can tell you have a passion for that kind of work and it shows.

It really did. I could've bought a brand new digital scope for what I sunk into it. On the other hand, analog is so much cooler. Circular analog screens even more so.

Restoration complete, several months and a few hundred bucks later... Had some brackets for a better scope tube and adapter plates with D-shaped holes made by eMachineShop.com. That was expensive. I was able to upgrade all the connectors to BNC connectors with the adapter plates though (they would h...