The Amp Garage

Fired it up with the new PS and BS caps, and adjustable bias. Sounds great, very low noise, but still no trem. I dont see any light being emitted by the roach, but didn’t get further. Next I’ll manually short the jack connection, check the v5 voltages, and swap the tube if it still doesn’t work. Did...

Just all of those CTS brand Alnico mag speakers are worth some good bucks by the way! Yeah, that originally caught my eye as a fallback if things were found to be bad with it, but so far so good. All 6 have the same date codes (40th week of 71). Someone with a silverface super reverb would want to ...

sluckey wrote: ↑Sat Mar 11, 2023 10:07 pm

BrownIsound wrote: ↑Sat Mar 11, 2023 9:20 pm Tremolo also doesn’t work.

You need the footswitch to enable the tremolo. Or, you can just ground the tip of the vibrato FS jack to enable.

I do have the Footswitch. Clicked the button a few times, but no tremolo. I “thought” I heard a very faint ticking during trying the switch.

Picked one of these behemoths up a couple weeks ago. Previous owner had said they used it as recently as last summer, so I did fire it up just to see how she sounded, and she sounded really nice, no noticeable hum or bad noises. Pots are very dirty when using them. Tremolo also doesn’t work. All Chi...

I ordered a quad of the Psvane for my superlead, so whenever I receive them and get to put them in I’ll report my findings, in the interest of science. What are your scientific findings ? They compare very favorable to a quad of mullards I have (a pair each of xf2’s and xf4’s that bias close to eac...

I was contemplating repurposing the standby switch as a “tube rectifier”/ silicone diode setting with resistor(s) and having the other half of the dpdt switch adjust the bias with a resistor to keep the bias current the same in both modes. The “tube rectifier“ setting giving you a slower inrush. Thi...

I ordered a quad of the Psvane for my superlead, so whenever I receive them and get to put them in I’ll report my findings, in the interest of science.

There’s a long post on the Marshall forum on this, with a circuit many people having made and liked, with several improvements. I have not yet made one, but it is on my list of things I want to do.
https://www.marshallforum.com/threads/s ... ing.98285/

Does anyone have any experience with an iso”closet”? I’m thinking like a multi purpose small room that could be used as a vocal booth, and house a 4x12 in it.

I’m not against doing a CCS, but since I have resistors on hand, that’s the easy way for now. I have only tried one of the calculated scenarios, but so far like it a lot, so I’ll play it during practice tomorrow to get a good feel of it before deciding to change it again. Ended up with 700/10k for t...

Here are a couple of on-line design guides for LTP: http://www.valvewizard.co.uk/acltp.html https://www.aikenamps.com/index.php/designing-long-tail-pairs-the-load-line-approach I did the calculations based on the valvewizard link to get a few scenarios. I’ll try some of them out this weekend, if th...

Yes, I was planning on starting with his suggestions. Haven’t had time to mess with it yet, hopefully sometime this week.

Trying to keep it as simple as possible, not much room under the hood. Will likely try experimenting with the resistor values on the PI for now. On a similar note, a post I found had an interesting point about connecting the cathode of the PI to a negative voltage (bias supply) to get the current/vo...

Just ordered ordered of these myself.

Does anyone have any other experience or updates on this type of tube tester?

Thanks.

Hi, I have made a home brew amp using 2 6BM8 tubes, assuming the triode halves act like a 12AT7, driving the pentode halves as a push pull pair, cathode bias. I used the silverface LTP values for the PI (47K plate, 270/22K tail), but I wonder if since I have quite a bit lower B+ than a silverface fe...