The Amp Garage

Not for nothing, but I did post to you that my original tank has the rca jacks grounded to each other thru the tank case😊 So your tank does not mount to the inside front lower wall as mine does? No. I have a Buckingham, not a Berkeley. This is the "big head" (as R.G. calls it) Thomas Vox. Same as t...

So while I was enjoying the amp earlier today with the reverb now working, I went a little crazy and cranked up the reverb blend for a real "soupy" type sound. I was just "exploring the reverb space", as it were. 8) In a further fit of craziness, I decided to also include some trem along with it, to...

OK... update. The 150 ohm input impedance tank measures DC resistance of ~29 ohms. The 600 ohm input impedance tank measures ~80 ohms. I guess I was tired last night. Upon closer inspection today, I missed that the 600 ohm tank in actuality has an insulated input. And the 150 ohm tank has a grounded...

From the chart that I have a input coil said to be 600 to 800 ohms impedance should resistance test at 58 ohms, is this the case with your new tank? I should have done this last night. I will confirm tonight. In terms of the hum you say you have and I assume your testing with things still apart tha...

I wonder if you are missing a ground for the input transducer with the "ungrounded input" tank? Yes, could be. Not sure if this is pertinent or I if I am interpreting the grounding/lack thereof with the inputs but when I looked at the inside of each tank (on the other side of the input jack), they ...

Congratulations! Getting the preamp working is about 90% of the work. Yes, and it was a LOT of work as you know R.G.. :shock: In the end, I did replace 97-98% of all the components in the preamp. The only original components are the inductors (MRB and the "Tone-X" channel), the three transistors in...

I have the preamp redone. 100% working. :mrgreen: Sounds pretty damn nice, actually! Pics later. I do have a question (below): I purchased a Mod reverb tank to use with the Buckingham as it never came with one. I ordered a 4EB2C1B. I wasn't quite sure I needed this one with input impedance (600 ohm)...

Update: I couldn't easily physically mount the toroidal power transformer on the Buckingham power amp chassis, so I went with the closest (electrically and physically) that I could find that would fit the chassis as is I settled on the Hammond 166L42 : https://i.imgur.com/oNralax.jpg I thought Hammo...

R.G., I suspected the higher gain devices would be fine in this application based on your other writings about it. I just wanted to know how/why. I really enjoy the explanation and the science behind the technology. I suspect I am not the only one and am continuing to learn things, which ultimately ...

It's been a while since my last post. Had a question as I start to go through the preamp and replace the channel input transistors. I have about twenty (20) new 2N5088s that I am checking gain/hfe, mostly out of curiosity and using this method (but adjusted for NPNs). They are all having gain in the...

Update on the preamp recapping. I had some spare radial electrolytics in the proper values so I jumpered them in. I have axials on order. Upon fire-up, the first thing that jumps out at me is the hiss... :cry: yes, I read this in R.G.'s Repair Supplement so it is no surprise... there's quite a bit o...

Yes, you are correct, I could not zoom in enough in your original photo I looked at. No worries, I had to triple check myself... :shock: Try not to use the mica type insulators under the TO3s. They insulate great from voltage but also heat transfer, this is why many of the windows in wood stoves is...

I just zoomed in on your photo and I replied wrong to you. Your red circles are on the collector terminal of the transistors, not the Base. I appreciate the follow-up but I do think I have it right. I even metered the socket terminals to verify. Here's a shot with a new socket placed above, oriente...

The cure I have found is to even out the impedance of the wire harness feeding these two or 4 output devices. Adding a 10 ohm 1/2 watt right on the Base lead of each output seems to do the trick nicely. Interesting Steve. I wonder what R.G. thinks. If I got it right, I'm inserting that resistor in-...

Typo in the last few sentences of my previous post:

I was hoping it was something *THAT WASN'T* exotic, like the Thomas driver transformer.