Hi audiofanatic,
Long time no speak..
Hope this helps.
http://www.builditmall.com/tubebuil...?page=scstore/results&Category=SEMICONDUCTORS
Regards,
Bas
Long time no speak..
Hope this helps.
http://www.builditmall.com/tubebuil...?page=scstore/results&Category=SEMICONDUCTORS
Regards,
Bas
Hi José,
Not many have tried em..but I have read only read positive reports
http://java.audioasylum.com/cgi/m.pl?forum=tubediy&n=34919&highlight=SCHOTTKEY+600V&r=&session=
http://www.audioasylum.com/cgi/m.pl?forum=tubediy&n=43623&highlight=SCHOTTKEY+600V&r=&session=
No worries mate! I still have to save up bucks to pay for em...so take your time..
Cheers,
Bas
Not many have tried em..but I have read only read positive reports
http://java.audioasylum.com/cgi/m.pl?forum=tubediy&n=34919&highlight=SCHOTTKEY+600V&r=&session=
http://www.audioasylum.com/cgi/m.pl?forum=tubediy&n=43623&highlight=SCHOTTKEY+600V&r=&session=
No worries mate! I still have to save up bucks to pay for em...so take your time..
Cheers,
Bas
Konnichiwa,
Well, I am currently using something like this in my main system.... It is based around many of Lynn Olson's ideas plus some of my own. The Amp has slightly less "magic" than SE, is a bit more literal. But it allows me to get good power with the sound of 45's which is worth something to me, but maybe not to you.
Circuit is 10K:10K+10K input transformer (S&B TX896) into 5687/E182CC differential into a prototype 40K CT : 40K+40K (S&B TX101 "High Level" - not yet available) Interstage into differential 45/2A3/300B with "semi-fixed bias" into 5k5 PP Outputs, +B is 320V with 2A3 or 300B with 60mA per output.
No real idea, except maybe the first stage balance may not be good enough by design to not saturate the IT. My design incorporates a bias balance pot for the Driverstage to make sure the interstage transformer has balanced currents as due to the 80% Nickel core it cannot tolerate much offset, parafeed would have been the other option.
Given what I have heard so far from high Voltage Valve SET's (or PP Amps indeed) I'd perfer such a PP Amp, personally speaking.
Sayonara
analog_sa said:
Well, I am currently using something like this in my main system.... It is based around many of Lynn Olson's ideas plus some of my own. The Amp has slightly less "magic" than SE, is a bit more literal. But it allows me to get good power with the sound of 45's which is worth something to me, but maybe not to you.
Circuit is 10K:10K+10K input transformer (S&B TX896) into 5687/E182CC differential into a prototype 40K CT : 40K+40K (S&B TX101 "High Level" - not yet available) Interstage into differential 45/2A3/300B with "semi-fixed bias" into 5k5 PP Outputs, +B is 320V with 2A3 or 300B with 60mA per output.
analog_sa said:
No real idea, except maybe the first stage balance may not be good enough by design to not saturate the IT. My design incorporates a bias balance pot for the Driverstage to make sure the interstage transformer has balanced currents as due to the 80% Nickel core it cannot tolerate much offset, parafeed would have been the other option.
analog_sa said:
Given what I have heard so far from high Voltage Valve SET's (or PP Amps indeed) I'd perfer such a PP Amp, personally speaking.
Sayonara
I've ordered Valve Amplifiers by Morgan Jones and the Radiotron Designers Guide so in the future I should be able to make an intelligent contribution here.
I am looking at Black Art Transformers for both output and Interstage. They are hand wound and available locally. In the future I may upgrade but they are good for now - particularly with local support.
How important is it to get really good chokes and power transformers? I would prefer to buy locally since the cost of transport is a real killer. A 10KG pack from the UK costs me 135 pounds UK. That is nearly as expensive as the parts themselves !! I can probably get all that made up here but I have no idea of the quality.
Thanks
Ralf
I am looking at Black Art Transformers for both output and Interstage. They are hand wound and available locally. In the future I may upgrade but they are good for now - particularly with local support.
How important is it to get really good chokes and power transformers? I would prefer to buy locally since the cost of transport is a real killer. A 10KG pack from the UK costs me 135 pounds UK. That is nearly as expensive as the parts themselves !! I can probably get all that made up here but I have no idea of the quality.
Thanks
Ralf
My few impressions seem to indicate Tamura iron being quite 'dark' sounding compared to Tango.
Chokes sound as different as caps. Would you have your local cap winder do your caps
? That said i haven't really used top quality chokes, but striving for low dc resistance, low flux and high nickel content seem all good things. I use a lot of old chokes by Partridge and Klangfilm and think a modern update is due.
Konnichiwa,
Try also to get hold of the RCA Raditron Handbook RC-10. It's floating around on the net as PDF File, well worth having both for the antique valve data AND for the technical section in the first pages, prbably more usefull than either of those you listed with SE Amp's.
In a zero feedback SE Amplifier with a high resolution speaker attached you can hear the difference between using copper or silver for a few inches of wire. Powersupply capacitors and Powersupply CHokes/Transformers also make a disproportionally contribution to the resultant sound.
Sayonara
DVDHack said:
Try also to get hold of the RCA Raditron Handbook RC-10. It's floating around on the net as PDF File, well worth having both for the antique valve data AND for the technical section in the first pages, prbably more usefull than either of those you listed with SE Amp's.
DVDHack said:
In a zero feedback SE Amplifier with a high resolution speaker attached you can hear the difference between using copper or silver for a few inches of wire. Powersupply capacitors and Powersupply CHokes/Transformers also make a disproportionally contribution to the resultant sound.
Sayonara
Hi DVDhack
Maybe the black art xformers are good.They're hand wound,this sounds pretty cool.But ask the winder how he wind them.
To hand wound a transformer it's too difficult and needs hours to finish one.This means that it must be expensive.
I'm only using double C cores hand wound transfomers from GK xfomers but the winder has told me that he spends minimum two days to wound one.But he knows what he is doing.
All production xformers are wound with winding machines and it's too difficult to make two xformers exactly the same.Go and see Bartolluci's site how he wound them.You will see that in the beginning of the winding the turns were more dense than a few centimeters after.And this is a big problem.
The turns must be the one exactly next to the other.
I have used Hammond,Lundahl,Bartolluci,Sowter and I never had these results I have right now.
Maybe the black art xformers are good.They're hand wound,this sounds pretty cool.But ask the winder how he wind them.
To hand wound a transformer it's too difficult and needs hours to finish one.This means that it must be expensive.
I'm only using double C cores hand wound transfomers from GK xfomers but the winder has told me that he spends minimum two days to wound one.But he knows what he is doing.
All production xformers are wound with winding machines and it's too difficult to make two xformers exactly the same.Go and see Bartolluci's site how he wound them.You will see that in the beginning of the winding the turns were more dense than a few centimeters after.And this is a big problem.
The turns must be the one exactly next to the other.
I have used Hammond,Lundahl,Bartolluci,Sowter and I never had these results I have right now.
protos said:
All in my very humble opinion ...
There's a lot of good engineering in there, in terms of the operating point of the 300B. This is worth a very careful read or three ....
I'm not sure about the use of a 12AX7. Simply, it is a poor sounding valve. It has high gain but so what, if the sound is lousy. There are other ways of getting high gain. Also, there is a poor tradeoff for the gain; very low current. This sometimes makes it hard to get the full performance from it. Avoid like the plague!
I have doubts about the driver stage. Active loading is used as a way to overcome some problems of the 12AX7 (high internal plate resistance).
However, the result is not good and still needs a cathode follower buffer to drive the 300B. OK, a quality CF is used; but it ends up as four valves to do the job of 2.
If one wants a high gain driver stage, this seems a lot better. A 6SL7 actively loaded with a pentode in a Kimmel mu stage has a low output impedance which will drive a 300B *fine*.
What's more, the 6SL7 is a good sounding valve. Configured well, the stage will have a very wide linear voltage swing. OK, the 6SL7 has a high plate resistance but careful choice of pentode load will give a low output impedance. Gain will be about 70 instead of 100 for the 12AX7, but that's not a lot really (half a notch on the volume control) and sound should be far superior.
I mention this 6SL7 approach as it has similarities to the cct in the link (high gain, active loading) and it is known to give good results (e.g in the Welborne Laurels). I must admit I use it myself in 'Valentine' so I'm biased.
Do remember, it is only one driver method, and no way would I claim it is best.
Summary: an odd mixture of good and bad, with the bad points then massaged to fix the problems. There are better ways.
The translation isn't too bad, just needs someone with a knowledge of valves and german/english to rehash the translation - it is the technical terms that get screwed up.
It make as much sense to me reading German as the translation - my german is as a 5 year old migrant to an english speaking country so I'm not familiar with enough technical german.
Anyone out there that could assist with a translation?
I'll try my mother but not sure she can grasp the technical terms.
Thanks
Ralf
It make as much sense to me reading German as the translation - my german is as a 5 year old migrant to an english speaking country so I'm not familiar with enough technical german.
Anyone out there that could assist with a translation?
I'll try my mother but not sure she can grasp the technical terms.
Thanks
Ralf
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