Thanks. Do you have a file with the schematic that will pull up in LtSpice? I’ve made a couple of changes and would rather not have to draw the whole thing if you’ve got something that will pull up that I can modify. Thanks. Kilo95 at aol dot com
Very interesting & beautiful diy work. I like the baxandall tone control instead of FMV tone stack (I'm currently working on a 4 bands tone control with baxandall topology for GUITAR AMP but with AOP OPA1641). This topology is rarely used in instrument amp because you have a flat response (and because it's more expensive). I think it's a mistake . However FMV tone stack adds a color to the sound because there is at 50% pot a no flat response (so a color to the original sound). Most of time this is a cut in the middle. With a baxandall tone stack, I think adding a FMV tone stack WITHOUT pot but instead fixed resistors with right values. This could be carried this color to the guitar amp (I will use tsc to find the fixed curve I want) and after that have a really better control of bands because of Baxandall tone control 😉
What software did you use for scm? it is very clear and easily reading. I like the layout of the SCM.
What software did you use for scm? it is very clear and easily reading. I like the layout of the SCM.
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Hello friends of creative crafts, I would gratefully like to contribute something to the thread. Now I tried out the circuit and it works wonderfully. I just don't use the V3a. You can still see the wiring in my photos, but it is only intended to show what a preamp like this in my version can look like from the inside. The solder joints look worse than they actually are in the pictures due to reflections and annoying shadows. But hey, this is DIY and not a masterpiece that will pass an engineering exam. I connected the 10uF capacitor to the 25K volume pot. All 3 tubes are JJ ECC803 S. The transformer I used was the TT-PWE 50 from Tubetown, which can be mounted horizontally. By the way, Tubetown also has a toroidal transformer with the same specifications. The Hammond case, innards and tube protection cages are also from Tubetown. I once got the circuit for the power supply from a good friend, and this in combination with the transformer has worked well for all of my tube preamps so far. This means that I don't have to do anything that Freddie's circuitry provides for screening. Only the resistors for the anodes remain. No hum or noise. The transformer for D.I. Out for me is Neutrik NTM4. I deliberately placed the jacks on the top of my preamp. This is very practical when performing on small stages where it is dark and there is hardly any space. But I usually put it on my Markbass bass cube and connect the output jack to the return effect.
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Hi Guys,
Some questions , bass player advice please.
I have 2 x Bass Quad boxes that I've been keen to do something with and this preamp seems to tick the boxes for the amps.
On the preamp - the control arrangement left to right shows
GAIN BASS SLOPE MID MIDSHIFT TREBLE VOL
whereas the JCM800
GAIN SLOPE BASS MID etc.
From a players perspective which is preferred.
For Power amps I thought I'd do 2 , one for each box . I have Hammond 1650T (120W HiFi) Output trannies.
The idea being that for small gigs you use 1 cab and 1 amp and for larger gigs you double up.
I have done 2 designs for the power amps which are VERY similar except
One uses a quad of KT88 with the option of Ultralinear connection with about 135 Watts (in Ultralinear).
The other design uses a quad of 6DQ6 pentode mode ONLY with 150W output.
Can you recommend one or the other for the poweramp design.
Thanks
Ian
Some questions , bass player advice please.
I have 2 x Bass Quad boxes that I've been keen to do something with and this preamp seems to tick the boxes for the amps.
On the preamp - the control arrangement left to right shows
GAIN BASS SLOPE MID MIDSHIFT TREBLE VOL
whereas the JCM800
GAIN SLOPE BASS MID etc.
From a players perspective which is preferred.
For Power amps I thought I'd do 2 , one for each box . I have Hammond 1650T (120W HiFi) Output trannies.
The idea being that for small gigs you use 1 cab and 1 amp and for larger gigs you double up.
I have done 2 designs for the power amps which are VERY similar except
One uses a quad of KT88 with the option of Ultralinear connection with about 135 Watts (in Ultralinear).
The other design uses a quad of 6DQ6 pentode mode ONLY with 150W output.
Can you recommend one or the other for the poweramp design.
Thanks
Ian