http://www.pbase.com/martymart/image/40836104/original
This is a "jpg" and should be fine when downloaded
circuit is verified.
Ground both jacks and voume lug one.
"Pre-gain" lug one is not connected.
Enjoy !
Marty.
As I have a few AC128's lying around could I just use those and reverse the electro caps and battery wires assuming the values of the rest of the components to be suitable
Yes that will work fine, remember to reverse the protection diode and Q1's 'leak' diode too.
try to find a 70hfe Q1 and 120hfe ish for Q2
Marty. 8)
Thanks for that, if only these AC128's are any good now !!!! I've also got about 6 OC44's which might be better for Q1, fingers crossed !!!!!!!
Quote from: BD13UKThanks for that, if only these AC128's are any good now !!!! I've also got about 6 OC44's which might be better for Q1, fingers crossed !!!!!!!
OC44's ..... Lucky man !! :D
Marty.
"BUMP" !!
Just didn't want this one to get "lost" !! :D
Marty.
OOOP's !!!!! I've only got 5 0C44's with the number 6541 marked on the side of them and the red dot, not 100% sure but I think there Philips, dont even know if there any good as yet as I haven't properly tried them out in a circuit as yet.
Take care of the dinosaur eggs, make certain they get not too hot, or see reverse polarity, or mispinout...I pretest boards with ROTM 3906 or something until it sounds like it wants to start.
Socket Input cap [output too?], and both transistor positions, trimpot Q2C...you should most probably be able to get a stellar FF happnin' there.
I'm glad to see that everyone is enjoying the Axis Face Germanium! It is easily converted to PNP Positive Ground is so desired...just remember to also reverse that Germanium diode that's attached between the base of Q1 and ground (along with all the other polarized components)!
If you like the Germanium version of the AF, then you'll most likely also like the Axis Face Silicon Rev. 3. That Silicon circuit seriously gets so close to the sound of the Germanium model that it's hard to tell the difference between the two when A/B'ing them. Best of all...you don't need to buy expensive Germanuim components any more! ;)
Phillip
Quote from: phillipI'm glad to see that everyone is enjoying the Axis Face Germanium! It is easily converted to PNP Positive Ground is so desired...just remember to also reverse that Germanium diode that's attached between the base of Q1 and ground (along with all the other polarized components)!
If you like the Germanium version of the AF, then you'll most likely also like the Axis Face Silicon Rev. 3. That Silicon circuit seriously gets so close to the sound of the Germanium model that it's hard to tell the difference between the two when A/B'ing them. Best of all...you don't need to buy expensive Germanuim components any more! ;)
Phillip
Thanks Phillip, I'll give the "Si" version a try ! :wink:
Marty.
Excellent Circuit, my FF's are close to or exactly that for the most part...Ge's still 'struggling', I tried working with it today...could just be me and mine, but I'm using an Si FF mucho these days.
MartyMart !!!!!! Would it be ok to use the existing NPN veroboard layout with Si trannies or would there need to be component changes if not using NPN Ge's.
Quote from: BD13UKMartyMart !!!!!! Would it be ok to use the existing NPN veroboard layout with Si trannies or would there need to be component changes if not using NPN Ge's.
You could probably loose the 10k trim pot and use an 8k2 or 6k8 resistor instead, then it should be fine !
Si NPN's dont need such fine "bias" anyway.
Try a BC549A Q1 and BC549C for Q2 or whatever you have !!
Marty.
I put that trim on, but you're right, there's a much wider range of ohms that tunes FF just fine'...cause I trim, I never measure the R value of Q2C...those values sound about right.
You can always start with the high value and trim it down with a parallel resistor and see what that does. I put socket there before, used insert pot to find the right value, measure, then insert correct fixed resistor.
Guess I just like diddling with trimpots...EZ after the board is mounted, then after it's boxed I interview transistors and caps, tuning it where the amp it'll use is.
Thanks again Guys !!!!!!!!!!!!