The Amp Garage

Hello, While I realize this is a topic that has been beat to death and easy to say "Google is your friend", I've found that nearly every type of search has lead to threads that don't seem to ever land on a solution that isn't marred with controversy. So, I'm going to try this a different way:. Has a...

Thank you all for chiming in on this, -definitely helped to sort things out, and give a few things to think about and inspect in the circuit. Pretty much any OT I've ever had, I've done the ac voltage ratio/winding ratio/impedance ratio/tap determination just to see for myself and give exercise to t...

Hi Martin and thank you. So, this probably tells me that when referring to the layouts of these amps, it is imperative to pay attention to which output tube the brown and blue wire go to as they will absolutely correlate to the specific phase inverter output wire. What is happening at the phase inve...

Hello, I was hoping for a sanity check or deepening of the understanding of what happens when the outputs of the phase inverter are not wired correctly. Does the problem have to do with the phase of the negative feedback causing a positive addition rather than a negative cancellation? It was one of ...

Thanks very much guys,

That is very good to know!

Best,

Phil D.

Hello, i was hoping someone would comment on the electrical aspects of whether the reverb tank is connected or Not connected, if there is any loading or "un-loading" that can be expected to make a sonic difference. Reason I ask is that I'm very close to finishing a single channel Pro Reverb type amp...

Glad I came across this thread.

Will be getting back to a 2204 build that's almost done and looking to experiment with mods to see which ones win.

This certainly looks to be something to try out.

Thank you,

PJD3

I'm glad to see this thread while getting ready to choose and purchase a new reverb tank for a "Blackvibe 6L6 to Deluxe Reverb (6L6WGB) with Reverb/no trem conversion project nearly finished. Its also looking like one will need to see about picking the "best of the crappy current production reverb t...

Thank you Martin and all for this info. And for the very nice and telling graph. This all helps put a couple of things in perspective for this. Next, I will be wondering if the Vox cut control can be opto-switched in and out for channel switching, reduce some highs in a very high gain Marshall type ...

I like that Sluckey. I Volt - removes a step towards the finding. Thats what I need at home. A variac. It's always a bit stressful when sparking up a new amp build with the "hope" that you did it all right. Of course, you can make up for that by going over the wiring 3 times (which I do) and testing...

Yeah, intuitively, applying that level of voltage to an output transformer is something I wouldn't have done, and likely would never do unless there was something in using 120vac that was going to tell me something relevant that 12vac would not. I've even wondered if applying the 12vac to the taps a...

Sounds like a higher voltage would be more revealing. I did do out the calculations for impedance ratio and then divide those into 4K and the results landed dead on the tap values (8 and 4 ohms) so, at least the identification was satisfied, which was mostly what I was after. Allen Amps did eventual...

Hi and thanks so much for your informative and generous responses. I have always wondered why I've seen the standard dropping power node resistors and choke for screens and preamp tubes but, never anything in terms of a resistor between the Rect tube and the first filter cap. Due to the total absenc...

OK, my post of shame, If you'd like to see: VAC in: 13.39vac to primary (brown and blue wire) Yellow/Black = .601 vac Green/Black = .43 vac Green/Yellow = .175 vac So, .601/.43 = 1.4 .601/.175 = 3.43 According to Martins values, my black wire is common, yellow is 8 ohms and the green is 4 ohms. I di...

Thank you all for such informative and insightful responses. I will pull out a 12volt transformer I have somewhere here and do the voltage/winding ratio/impedance measurements and calculations. I've done that on a few OT's and its always landed the results nearly dead on the usual tap impedance's. A...