Hello everybody,
I'd like to build tube amplifier on my own and I had chosen Ampeg SVT, but have a problem with schematics:
On the Internet I can only find an old SVT schems (http://users.aol.com/bluemuse/ampeg.html -SVT preamp and SVT poweramp). that uses 12DW7, 12BH7, 12AX7 & 6C4 tubes in preamp and driver stage. This times it's very hard to find 12DW7 & 12BH7, even impossible in my country :/
Does anybody have the new schematics (with 2x12AX7+ 12AU7 in preamp and 12AX7 + 2x12AU7 in driver) or can just adjust the older schematics to use only 12AX7 & 12AU7 (and maybe EL34 in amp stage) against 12DW7, 12BH7 and 6C4?
I'll be enjoyed with every help
--
Peace
I'd like to build tube amplifier on my own and I had chosen Ampeg SVT, but have a problem with schematics:
On the Internet I can only find an old SVT schems (http://users.aol.com/bluemuse/ampeg.html -SVT preamp and SVT poweramp). that uses 12DW7, 12BH7, 12AX7 & 6C4 tubes in preamp and driver stage. This times it's very hard to find 12DW7 & 12BH7, even impossible in my country :/
Does anybody have the new schematics (with 2x12AX7+ 12AU7 in preamp and 12AX7 + 2x12AU7 in driver) or can just adjust the older schematics to use only 12AX7 & 12AU7 (and maybe EL34 in amp stage) against 12DW7, 12BH7 and 6C4?
I'll be enjoyed with every help
--
Peace
I haven't checked completely myself but this site has a lot of Ampeg schematics
http://www.drtube.com/guitamp.htm
http://www.drtube.com/guitamp.htm
I've got a VT-22 that if I remember correctly uses 12AX7A, 12AU7A, 6AN8A, 7027A and maybe one other common tube... none of the schematics I can find online now match it, I'm pretty sure I found one a few years back though.. I can try to hunt it down if you're interested.. it'll probably mean taking an old PC out of mothballs 😉
You can adjust them for more comon tubes, but the 12bh7 and 12dw7 are still being manufactured in russia... AND right over your boarder in the Czech republic, so i don't see why you can't get those in Poland.
The 12DW7 is simply 1 of 12AX7 triode section (pins 6,7 and 8) and 1 of 12AU7 triode section (pins 1, 2 and 3) stuffed into a single envelope. If you are building from scratch it should be easy to adapt.
Cheers,
Ian
Cheers,
Ian
Weird triodes
I can not get any in polish interent shops. It is possible, that they product this tubes only for The States and another west countries and that why they are unreachable in polish suplliers.
aletheian & gingertube : Yes, I can adjust the circuit to the new tubes and I know that they are simply mix of two types, but I'm looking for the new schematics, also because It contains less tubes and it would be less complicated and cheaper to build.
So radtech if you can send it, I would be very interested with this VT22 schem.
Thanks for all replies.
I'm still looking for these schematics
I can not get any in polish interent shops. It is possible, that they product this tubes only for The States and another west countries and that why they are unreachable in polish suplliers.
aletheian & gingertube : Yes, I can adjust the circuit to the new tubes and I know that they are simply mix of two types, but I'm looking for the new schematics, also because It contains less tubes and it would be less complicated and cheaper to build.
So radtech if you can send it, I would be very interested with this VT22 schem.
Thanks for all replies.
I'm still looking for these schematics
radtech said:
You have a VT22 that DOESN'T use a compactron? THAT i would like to see. those are rare as a dragon's tooth.
Ampeg will e mail you any schematic that you need. I have a schem for an SVT-3 pro left over from a repair job... if you need it, i can send it to you. it has a SS power amp, but the preamp is classic SVT, but without the 12DW7mroovka said:
SVT-3 schematic
I also have this one, but svt-cl and svt-vr have 2 channels in preamp. I'd also like to know, how is driver in this amps designed.
I was looking for e-mail on Ampeg site, but I couldn't find it on the contact site. Today I found it on the support site. We will see what they think about giving these schematics.
I also have this one, but svt-cl and svt-vr have 2 channels in preamp. I'd also like to know, how is driver in this amps designed.
I was looking for e-mail on Ampeg site, but I couldn't find it on the contact site. Today I found it on the support site. We will see what they think about giving these schematics.
aletheian said:
So I finally got around to digging the amp out, and it seems my memory of it was a bit faulty, it does inded have the 12DW7 tubes.
Here's what it's got:
1 - 12AX7A
1 - 6AN8A
1 - 6CG7
3 - 12DW7
4 - 7027A
So it's not what I thought, apparently I had remembered the 12DW7s as 12AU7s, but still, no compactron!
Ah yes, i remember now. The compactron is on the onw with the echo (reverb) unit.radtech said:
this must be the one you have:
wow... took me a minute to find it, but sure enough, there it is... capacitor coupled from the 6CG7.
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