So yeah... shielded wire (big jump in this thread but it makes sense in the context of mine ?). Useful for longer runs and early stages that are going to be heavily amplified. Your google foo may be better than mine but this is the only place I could find it. https://raru.co.za/musical-instruments/6749035-allparts-7-5m-single-conductor-shielded-wire-silver
Long lead time though.
How To Build A Tube Amp, or Burn down A house.. Phase 1 the Research.
@Tuckstir Drop me a email. brj217@gmail.com. I might have something for you that will interest you.
Yeti Unfortunately I don't have a link for it and don't even know where it is from because I'd love to read the rest of the book.
I’ve found it! Turns out it’s one of the sites I linked to in an earlier post (although that isn’t where I got it). Trying to get hold of the book but it doesn’t seem to be available as an ebook.
http://www.valvewizard.co.uk/Book1.html
Tuckstir Thanks for the link, I hadn't tried that.
My google foo failed spectacularly. Just pages and pages of SEO sites with no real content. I did find one on scribd but I cancelled my subscription a few months ago. Incidentally, I contacted the author directly and he confirmed that there isn't an official electronic version. He did send me this link however and told me that I'd find most of it there.
https://www.google.com/search?tbm=bks&q=merlin+blencowe
Hi, Tedibear. I have a full 18W Plexi schematic and a copy of the book Electronics for Guitarists, which has a chapter on tube power amp design, if you are interested.
Johnny-B
I wont say No..
I have A google drive that can be accessed if you want any Books and stuff.
How can I add the documents to your Google Drive Amps folder?
Documents uploaded.
A question for the more electrical minded folks.
on the 2 Princeton schematics I posted above i noticed the bias's are different.
Princeton AA1164 uses a self-correcting Bias
vs
Hoffoman Princeton which uses a fixed bias.
From what I understand the fixed bias is trickier to set up correctly as it calls for a good ear, some hardware I don't own and something down right dangerous..
so why would I good for a fixed over a self-correcting bias, are their any real/perceived advantages of one over the other?
- Edited
I'm far from an expert and have only really done fixed bias myself... so again, pinch of salt.
What I understand is that fixed bias gives you more control.
1) You can vary the bias by twiddling a pot rather than swapping out resistors (although I suppose there is nothing stopping you from using a variable resistor in cathode bias).
2) As the bias is set externally it does not vary with loading like a cathode bias does so it keeps things more consistent (good or bad depending on what you're looking for).
From http://www.valvewizard.co.uk/pp.html
"Cathode bias often lends a natural compression or 'squishiness' to the sound, due to the increase in bias voltage when one valve enters Class B conditions, though the larger the bypass capacitor, the less will be this effect. A small capacitor (less than 100uF say) also increases non-linear distortion, which may be significant in hifi. Using a very large capacitor (greater than 470uF say), or using no capacitor at all, reduces this effect.
Fixed bias on the other hand, remains the same at all times. This allows maximum output power to be developed, and the reduced compression gives faithful transient response, or a stiff or 'barking' overdriven sound.
Furthermore, there is no reason why we cannot use a little fixed bias and cathode bias simultaneously to achieve the desired mix of compression and 'bark'. "
If you're interested, this is the method I used to generate my bias voltage... and to be honest, I just set it to the nominal value from the schematic and left it there. It sounds pretty sweet so I haven't been inclined to fiddle.
https://robrobinette.com/Generic_Tube_Amp_Mods.htm#High_Voltage_Tap_Adjustable_Bias
Out of interest, one nice side effect of using cathode bias is that you can use VVR to do power scaling and get some really good tones at low volume.
18 days later
So nothing much in the way of progress, Life is a bit distracting with other proprieties ATM
however a little birdie just dropped this off.
although I have a few books on amps, In digital, for reference books I prefer to have a physical copy.. just makes it easier to flip back and forth.. so now I have some heavy bedtime reading.. ?