The Amp Garage

I have been corresponding with Nik, who btw is extremely helpful and service minded towards his customers. However we've progressed far beyond that correspondation in troubleshooting here. He can offer me a good deal on Mercury Magnetics. I'm having some troubles with the PT on my second hand OTS a...

FWIW I built my Dlator with a transformer I got from Nik many years ago. Not sure of the quality, but still working! In my various iterations of Dlator over 12-14 years, it has always been externally mounted on the rear panel as per the Dumble ones. The only problems I've had has been with switching...

What I was asking is if the C-lator is connected to the amp, is the hum affected if you remove either of the "preamp out" or the "power amp in" cables. Just tried: Hum is introduced when connecting the C-lators out to the "power amp in". So: No C-lator = no hum. C-lator in to " Preamp out" = no hum...

Interesting that you found the 10Ks a better option. I haven't got LTSpice but I ordered a couple of pots to see if I could see/feel/hear any difference.
Thanks and good that you are refining your project.

If you contact Ronald and send him the screenshots, I'm sure he will give you some test checks to run. Is there someone who might be able to help with my new utracer 6? It passed the tests during construction and I completed the cal section fine but it appears not to function for me testing tubes. I...

It lives! Not amazingly tidy and neat but working well. I fired it up with TL072 and it sounded really good and quiet. When I was sure it was working, I changed it for the OPA. I can't say I can hear much difference. A really nice build, very enjoyable and some good planning and thought gone into th...

Hey Ryan, the boards arrived today and look really good. The faceplate is also a very nice touch too. I wanted to lacquer it to protect the screen print but was afraid of dissolving it so covered with clear adhesive plastic instead. EDIT: the clear plastic looked bad so I hit it with clear nitro, it...

Yes, sorry for the delay. Heads down on the accompanying documentation. Based on my calculations, the 1m bias resistors are good to go. I have them in my prototype and it's very stable. The bias for the opa2134 is in the pico-amps so not much needed if you're using that chip. I'm using OPA2134, wha...

Good catch. Just updated the link with the correct mouser project. I am updating the circuit today to add the bias resistors. 🕺 Standby .. Hi Ryan, any progress? I saw the bias resistor updated boards on the gallery , lookin good! Hey Rogb! Yes! I received 50x board sets today with the bias resisto...

Good catch. Just updated the link with the correct mouser project. I am updating the circuit today to add the bias resistors. 🕺 Standby .. Hi Ryan, any progress? I saw the bias resistor updated boards on the gallery , lookin good! Hey Rogb! Yes! I received 50x board sets today with the bias resisto...

The BB should be good still. You just need to remove the bottom nut on your footswitch. I'm building my next one in a BB size Excellent, thanks. Let us know if you are going to bias the op amp as suggested. I know it's only the v1 BOM, but I don't think the Mouser project link is the correct one ye...

Really neat work! I love your rig. Once you go rack, you can never go back! First pic is with the 200w per side Class D stereo power amp, but I couldn't resist an all tube 20/20 rig in the end! The Palmer Macht does have some slam though, and I'm keeping it. Wow, that looks nice rogb! Did you tweak...

Really neat work! I love your rig.
Once you go rack, you can never go back!
First pic is with the 200w per side Class D stereo power amp, but I couldn't resist an all tube 20/20 rig in the end!
The Palmer Macht does have some slam though, and I'm keeping it.

The BB should be good still. You just need to remove the bottom nut on your footswitch. I'm building my next one in a BB size Excellent, thanks. Let us know if you are going to bias the op amp as suggested. I know it's only the v1 BOM, but I don't think the Mouser project link is the correct one ye...

Fair point! Thanks for chiming in! I think a 220k to ground right at the input of both sides of the op amp would be a good balance of predictable bias and Johnson noise. I'll do some math later too. Easy to mod these boards I have as well. Good thing I only ordered 5x. Now I'll have to leave this a...