Hello everybody!
I own a pair of VTL Compact 100 Monoblocks that use 2 x 12AT7 & 4 x EL34 tubes. I'm quite satisfied with the sound they produce
but few years ago one of their volume became very small that I
have to move myself pretty close to the speaker to hear the sound. At the same time a hi-fi shop is on sale and I bougt a pair
of Audio Resource power amp so that I can still listen to my CDs. I've been using the Audio Resource model Amp One since then (
that was 1997 or 1998) and they are still working normally. Since
I have some basic knowledge of electronics, I intend to fix the VTL myself. The biggest drawback is my lack of experience (also lack of time) that keep me from starting the project for so many years.
I should be grateful if you would please:
1. share that kind of experiences,
2. show the test report or review, if there's any,
3. suggestions of modifications to make it sound even better,
4. the way you think of its sound quality.
All best wishes!
The other audios that I have:
Sansui CD Alpha 717-Extra cd player,
Marantz CD-63 II KI,
Dynaco PAS3,
Spendor Prelude,
Linn LP-12 Export,
SME-3009 III,
DIY 12AU7 preamp,
DIY 6AN8 + EL84 power amp.
I own a pair of VTL Compact 100 Monoblocks that use 2 x 12AT7 & 4 x EL34 tubes. I'm quite satisfied with the sound they produce
but few years ago one of their volume became very small that I
have to move myself pretty close to the speaker to hear the sound. At the same time a hi-fi shop is on sale and I bougt a pair
of Audio Resource power amp so that I can still listen to my CDs. I've been using the Audio Resource model Amp One since then (
that was 1997 or 1998) and they are still working normally. Since
I have some basic knowledge of electronics, I intend to fix the VTL myself. The biggest drawback is my lack of experience (also lack of time) that keep me from starting the project for so many years.
I should be grateful if you would please:
1. share that kind of experiences,
2. show the test report or review, if there's any,
3. suggestions of modifications to make it sound even better,
4. the way you think of its sound quality.
All best wishes!
The other audios that I have:
Sansui CD Alpha 717-Extra cd player,
Marantz CD-63 II KI,
Dynaco PAS3,
Spendor Prelude,
Linn LP-12 Export,
SME-3009 III,
DIY 12AU7 preamp,
DIY 6AN8 + EL84 power amp.
Hi there,
How old are the tubes??
Try to retube yet??
If so, are all working voltage correct?
Lhchen
How old are the tubes??
Try to retube yet??
If so, are all working voltage correct?
Lhchen
Hello Contaxchen,
I've tried another set of tubes and also checked the B+ voltages
on both amps, the measured values are quite the same (~430V),
and the tubes look ok too.
Thanks anyway!
I've tried another set of tubes and also checked the B+ voltages
on both amps, the measured values are quite the same (~430V),
and the tubes look ok too.
Thanks anyway!
Hi,
Check out this link. It was written in simplied Chinese.
http://www.tvdiy.net/hifi/yx9.htm
Well, if all working voltage is correct, then the problem is big.
I have a pair of VTL M100, too. Like 18 years old.
Lhchen
Check out this link. It was written in simplied Chinese.
http://www.tvdiy.net/hifi/yx9.htm
Well, if all working voltage is correct, then the problem is big.
I have a pair of VTL M100, too. Like 18 years old.
Lhchen
Here's a stab at it: possible bad cathode bias resistor bypass capacitor on the 12AT7 AF amp (1st stage) or a bad grid bypass cap on the 12AT7 LTP phase splitter. Also check the coupling caps to the EL34's. And IIRC since the VTL's use PCB's, look for cold/bad soldier joints.
Wayne
Wayne
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