QUICKSILVER.
Hi Joe,
The circuitdiagram for the amp could be drawn in less then ten minutes by a competent technician.
The beauty of that amp is it's sheer simplicity,just a pair of coupling caps and a handful resistors.
None of the customers got the circuitdiagrams with their amps,not even the dealers as I recall it.
Ciao,
Hi Joe,
The circuitdiagram for the amp could be drawn in less then ten minutes by a competent technician.
The beauty of that amp is it's sheer simplicity,just a pair of coupling caps and a handful resistors.
None of the customers got the circuitdiagrams with their amps,not even the dealers as I recall it.
Ciao,
Frank
Not knowing much about tube equipment I found the Quicksilvers to be very pleasing to the ear. I was surprised at the amount of bass and the bass wasn't quite as sloppy as the reviews that I had read. The midrange was quite warm and the highs pleasing. Honestly, it put my SAE X25A(class A poweramp) to shame. I'm glad I offered the guy I bought the amps from the little extra it took to get them. The reviews I've read on the amps seem dead on. I believe that you were right also, they are a good sounding amp.
Now, Ive got to finish selecting my parts to assemble my preamp.
Here is a picture of the guts.
Not knowing much about tube equipment I found the Quicksilvers to be very pleasing to the ear. I was surprised at the amount of bass and the bass wasn't quite as sloppy as the reviews that I had read. The midrange was quite warm and the highs pleasing. Honestly, it put my SAE X25A(class A poweramp) to shame. I'm glad I offered the guy I bought the amps from the little extra it took to get them. The reviews I've read on the amps seem dead on. I believe that you were right also, they are a good sounding amp.
Now, Ive got to finish selecting my parts to assemble my preamp.
Here is a picture of the guts.
Attachments
FROM WHAT WE SEE
Hi Joe,
Your amp has been modified already.
Maybe by Quicksilver themselves,maybe by the previous owner?
At the lefthand side top you see the two coupling caps that are now MIT Multicaps.
The yellow ones are unchanged and bypass the PSU caps.
Most of the resistor look a lot like the Roederstein Resista and these are fine to my ears.
Other than that you see a few Philips metaloxide resitors,a couple of mica caps,all in all nothing really harmful to the sound.
I always found the bass excellent,even exceptionally good on these amps.
The highs should be a bit more open now thanks to the MIT caps.
Do you want the best 6550's for these?
Get a set of matched Tungsols,these are by far the best I ever heard by a long shot.
Magic!
And please don't buy all of what you find...I need about fifty of those a year.
Glad you're happy with your purchase Joe,
Hi Joe,
Your amp has been modified already.
Maybe by Quicksilver themselves,maybe by the previous owner?
At the lefthand side top you see the two coupling caps that are now MIT Multicaps.
The yellow ones are unchanged and bypass the PSU caps.
Most of the resistor look a lot like the Roederstein Resista and these are fine to my ears.
Other than that you see a few Philips metaloxide resitors,a couple of mica caps,all in all nothing really harmful to the sound.
I always found the bass excellent,even exceptionally good on these amps.
The highs should be a bit more open now thanks to the MIT caps.
Do you want the best 6550's for these?
Get a set of matched Tungsols,these are by far the best I ever heard by a long shot.
Magic!
And please don't buy all of what you find...I need about fifty of those a year.
Glad you're happy with your purchase Joe,
Re: FROM WHAT WE SEE
more groovy than ever before! 
I love to have you with me, fdegrovefdegrove said:Hi Joe,
Your amp has been modified already.
Do you want the best 6550's for these?
Get a set of matched Tungsols,these are by far the best I ever heard by a long shot.
Magic!
Glad your happy
more groovy than ever before!
Frank
Your just downright amazing. When I talked to the gentleman at Quicksilver and gave him my serial numbers he told me the amp had been modified to accept either 12FQ7 or 12BH7 tubes on the front end. From looking at the work/solder joints I knew the amp must be modified. The two caps didn't match the other Quicksilver brand caps. The amp is very good sounding. Is there any other improvements that could be made?
Joe
Your just downright amazing. When I talked to the gentleman at Quicksilver and gave him my serial numbers he told me the amp had been modified to accept either 12FQ7 or 12BH7 tubes on the front end. From looking at the work/solder joints I knew the amp must be modified. The two caps didn't match the other Quicksilver brand caps. The amp is very good sounding. Is there any other improvements that could be made?
Joe
GENIE IN A BOTTLE
Hi Joe,
There are ways but that really would require your acceptance of Moore's law.
Look,here is what I did for a dealer in Brussels many years ago:
The man being totally enamoured with the amps,even more so after a first mod, asked me what I would do to make them better still.
Listen good,it pays:
I told him it was going to cost him at least 250$ per mono block.
He accepted it and I went to work,all tube sockets were replaced with ceramic insulated ones and gold plated triple contact ones (you wont find these anymore,only 13.000 were made for us on special order by Schurter in Switzerland).
Any Russian ceramic octal and noval socket is very good though.
Next,all soldering supports were replaced with ceramic ones with silvered contacts.
Every passive component was removed and replaced with the same value but tighter tolerance and wirewrapped and soldered with leadfree high silver content solder.
All tubes were tightly matched and biased while taking OPT inbalance into account.
Any wiring was replaced with the best silver wire.
All PSU caps were upgraded by the best we could find,105*C Nichicons matched for equal and lowest ESR possible.
The amps were then burned in for a week.
The man payed the bill and sold all of them a month later at 500$ over regular price.
A month later we got 50 Jadis amps of all kinds,Ja30,60 to 200 in for a similar upgrade.
I say this was a lot of work but it did put the company on the map worldwide!
And that was 1989 or thereabout....
A year later we had the Japanese ringing the doorbell.
I'm convinced that a lot of our members can tell you similar stories.
Bottom line is...do you really want to push things that far?
Ciao,
Hi Joe,
There are ways but that really would require your acceptance of Moore's law.
Look,here is what I did for a dealer in Brussels many years ago:
The man being totally enamoured with the amps,even more so after a first mod, asked me what I would do to make them better still.
Listen good,it pays:
I told him it was going to cost him at least 250$ per mono block.
He accepted it and I went to work,all tube sockets were replaced with ceramic insulated ones and gold plated triple contact ones (you wont find these anymore,only 13.000 were made for us on special order by Schurter in Switzerland).
Any Russian ceramic octal and noval socket is very good though.
Next,all soldering supports were replaced with ceramic ones with silvered contacts.
Every passive component was removed and replaced with the same value but tighter tolerance and wirewrapped and soldered with leadfree high silver content solder.
All tubes were tightly matched and biased while taking OPT inbalance into account.
Any wiring was replaced with the best silver wire.
All PSU caps were upgraded by the best we could find,105*C Nichicons matched for equal and lowest ESR possible.
The amps were then burned in for a week.
The man payed the bill and sold all of them a month later at 500$ over regular price.
A month later we got 50 Jadis amps of all kinds,Ja30,60 to 200 in for a similar upgrade.
I say this was a lot of work but it did put the company on the map worldwide!
And that was 1989 or thereabout....
A year later we had the Japanese ringing the doorbell.
I'm convinced that a lot of our members can tell you similar stories.
Bottom line is...do you really want to push things that far?
Ciao,
Frank
To be honest I'm looking for mods that can give measureable results. I guess I can't subscribe to a mod unless it can be shown to provide measureable results. Years ago I went thru the typical tweeks that some of us SS guys suffered. The perfect capacitors with copper leads that had to be of a specific composition that someone thought would bring sonic joy. The bypass caps on every electrolytic cap in the signal path. The additional caps in the power supply with a soft start so one didn't turn the lights out in the house when you turned on the amp. Yes, we can't forget the wonder solder. Where does it all end? I put everything one could imagine into my amps until one day when I decided to measure the difference between a modified amp and a stock amp. That indeed was a scary day that proved no measurable increase in performance, no decrease in THD or IMD. When I could no longer obtain pleasure from any piece I went on a new kick, I built my own amp, a toy that laughed at any load presented and asked for more.
Where does it end?
To be honest I'm looking for mods that can give measureable results. I guess I can't subscribe to a mod unless it can be shown to provide measureable results. Years ago I went thru the typical tweeks that some of us SS guys suffered. The perfect capacitors with copper leads that had to be of a specific composition that someone thought would bring sonic joy. The bypass caps on every electrolytic cap in the signal path. The additional caps in the power supply with a soft start so one didn't turn the lights out in the house when you turned on the amp. Yes, we can't forget the wonder solder. Where does it all end? I put everything one could imagine into my amps until one day when I decided to measure the difference between a modified amp and a stock amp. That indeed was a scary day that proved no measurable increase in performance, no decrease in THD or IMD. When I could no longer obtain pleasure from any piece I went on a new kick, I built my own amp, a toy that laughed at any load presented and asked for more.
Where does it end?
Attachments
Quicksilver 8417 schematic
I don't know about the KT88 amp, but I used to own one of the 8417 amps. It was a nice simple amp, although its power supply had too much capacitance for the GZ34 rectifier. Based on the picture you posted, they look to be very similar. You can find the schematic on C. Bonavolts site.
---Gary
I don't know about the KT88 amp, but I used to own one of the 8417 amps. It was a nice simple amp, although its power supply had too much capacitance for the GZ34 rectifier. Based on the picture you posted, they look to be very similar. You can find the schematic on C. Bonavolts site.
---Gary
Attachments
8417-KT88 Changes
Ned of Triode electronics has published a small blurb explaining how to convert an 8417 amp to KT88. It also contains useful suggestions on fixing problems with the original 8417 amp. In a nutshell, the 8417 amp used too much capacitance for the GZ34 rectifier. It also used somewhat underrated coupling caps to the output tubes. And it used too high a value of grid resistance for the 8417, which made it useable only with certain brands of 8417. Take a look at:
http://www.triodeel.com/8417.htm
---Gary
Ned of Triode electronics has published a small blurb explaining how to convert an 8417 amp to KT88. It also contains useful suggestions on fixing problems with the original 8417 amp. In a nutshell, the 8417 amp used too much capacitance for the GZ34 rectifier. It also used somewhat underrated coupling caps to the output tubes. And it used too high a value of grid resistance for the 8417, which made it useable only with certain brands of 8417. Take a look at:
http://www.triodeel.com/8417.htm
---Gary
Attachments
I only see the 8417 schematic. As far as a modification, how about partial cathode coupling by grounding the 4 ohm tap and running the cathodes of the output tubes through the common and 16 ohm taps? Then reduce the feedback. See this link http://www.montagar.com/~patj/mi12188a.htm
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