Kamis,
The argument for and against vacuum tube equipment has been going on for a long time. I can agree that some tube equipment is more of a tone control than a truly sonicly neutral design but I must say that there are designers that can create a tube preamp or power amp that is as electrically correct as many SS designs. You just can't lump them all together and say they are all of the same quality of design or accuracy.
That being the real case doesn't mean many want to deal with the heat from vacuum tubes or the necessity in some designs to need to replace those expensive tubes. There are designs though that can last for decades with the same tube compliment, they are designed to a level of expertise where the tubes just last forever it seems, those may be rare but so are the properly designee SS designs where the designer gets it all right.
Dogma on either side of SS or vacuum tube design is really the same. Either way you do need to understand reality, there are way to many in this hobby who just want to believe that some magic part will change everything. there really is no magic beyond the imagination of a truly knowledgeable circuit designer. I would trust anything that Mr. Wurser designed, I know it would be designed with real understanding and testing to back up the theory. I wouldn't have much trust in those who change every cap to a particular brand or who insists that they have some magic wires. If someone can hear the difference between a soldered connection and a simple electrical connector something is wrong somewhere.
The argument for and against vacuum tube equipment has been going on for a long time. I can agree that some tube equipment is more of a tone control than a truly sonicly neutral design but I must say that there are designers that can create a tube preamp or power amp that is as electrically correct as many SS designs. You just can't lump them all together and say they are all of the same quality of design or accuracy.
That being the real case doesn't mean many want to deal with the heat from vacuum tubes or the necessity in some designs to need to replace those expensive tubes. There are designs though that can last for decades with the same tube compliment, they are designed to a level of expertise where the tubes just last forever it seems, those may be rare but so are the properly designee SS designs where the designer gets it all right.
Dogma on either side of SS or vacuum tube design is really the same. Either way you do need to understand reality, there are way to many in this hobby who just want to believe that some magic part will change everything. there really is no magic beyond the imagination of a truly knowledgeable circuit designer. I would trust anything that Mr. Wurser designed, I know it would be designed with real understanding and testing to back up the theory. I wouldn't have much trust in those who change every cap to a particular brand or who insists that they have some magic wires. If someone can hear the difference between a soldered connection and a simple electrical connector something is wrong somewhere.
No that's the norm for years, Kamis actually got it right with a z but my family changed it to not sound German (WWII). The name essentially does not exist in any culture so folks connect with anything close. The anecdote is actually buried in an interview with my father's B17 navigator youtubed just before he passed away.
Ours enjoys marrying to distant (or not so distant) relatives who still own property in the fatherland.
At the risk of the usual brickbats I wanted to show the simple diff-out idea. I've basically started with Bob Cordell's LA article and heavily Muntzed it adding diff-out and doing it with just JFET's. I've partially stuffed the boards and it looks good so far. The one FET sets the output common mode and keeps the differential-ness as good as the component match i.e. it does virtually no work. The distortion is admirable even at 10V p-p out into 2k using simple complementary source followers.
It was easier than I thought to go through only 20 each SK170's and SJ74's and match up enough for each position in two channels. The criterion I used was source resistor for exactly the desired operating current weather or not there was a source resistor. The source followers were picked so the N and P used the same standard value resistor for 5mA Id. This worked out great no trims, no offset, and very low distortion. No Vp or Idss matching at all. It remains a project to see how close this gets to the distortion null with a trim.
Note: this circuit is Muntzed no extra cascodes and resistors where some might want current sources. Also the DIFFERENTIAL PSRR is what matters and it is actually pretty good even though the common mode PSRR is 0 (RTO). SIM says 110dB RTI even at 20K (that won't be, but haven't measured it).
I've spent all of $60 for two boards and a set of surplus 1-2% TRW PS caps to put this onto my $179 U-Turn turntable as an exercise in minimalism.
Attachments
Last edited:
Still trying to work out who the UK equivalent of Muntz would be. Amstrad possibly. or Sinclair. neither of which have that ring to them.
Interesting.... my father was a navigator in B17's. Was the last man standing from his original group when the war ended. DFC from Dolittle etc.
After all that, Leukemia did him in.
In remembrance and honor to him, i use his initial in my signing (N).
-RNM
Last edited:
I can only assume that you have never listened to a decent valve amp; perhaps you think all valve gear sounds like a cheap Chinese 'tube buffer'?kamis said:
I have the moral right to make any comment which I believe to be true, relevant and not personally insulting. I am the judge of what I believe to be true; the Mods are the judge of relevance and what is personally insulting.
Good circuits usually don't need particular valve makes - except where low noise is an issue.
I think you will find that in the absence of NFB most valves can manage better linearity than any BJT. With NFB both are good enough for sound reproduction.
I don't think I mentioned the placebo effect, but that is a possible explanation. "Rigid theorists" use sufficiently good active devices, enhanced by negative feedback.
A cable plus its connectors form part of a fairly trivial potential divider. Unless the cable or the connector is faulty (or far too long for the source driving capability) then it cannot affect the sound; circuit theory says so. 'Ears-only' listening tests confirm this. So we have theory and practice agreeing; only sighted anecdote disagrees. It may be worth paying more for more reliable connectors, but not for better sound.
Everyday triodes with lightly-loaded anodes are very low distortion even open-loop, provided that they are operated in an optimal region far from cutoff. For some applications the Miller effect will entail too-high capacitance at the grid. And of course they are microphonic to varying degrees. The 1/f corner is also depressingly high frequency and highly variable among samples.
They are cumbersome given the heater power, and electron emission will decline with age, so they do deteriorate.
I like them, but I depart from thinking of them as in some way magical, as do some of my friends.
Tim deP has stated iirc that he can make tube-based or solid-state-based electronics sound like anything he wants. I suspect he is right.
They are cumbersome given the heater power, and electron emission will decline with age, so they do deteriorate.
I like them, but I depart from thinking of them as in some way magical, as do some of my friends.
Tim deP has stated iirc that he can make tube-based or solid-state-based electronics sound like anything he wants. I suspect he is right.
I have never built Chinese tube buffer, but I built Erno Borbely EB-1195/221 phono stage with J-Fet MC input hybrid phono stage which is non feedback passive RIAA, fully regulated with two stage regulators, heaters soft start circuit etc.
Low noise , no hum , but sound is softer and not so neutral as All-fet phono.
According to your circuit theory, amps with the same specs. must sound the same.Published specs. of EB-1195/221 are worse than all-fet phono and reproduction should be degraded.
I'm all for tubes in certain circumstances. I just added a triode based amp to drive my added tweeters, and it works just great for the application. When selecting a tweeter amp (above 8KHz) most solid state amps are either too slow, have too much Xover distortion, or too powerful. 15W/ch is OK with me in this application. My smallest commercial amp has about 10 times more power, and has some Xover distortion. Class A is the best, and this is most closely approached with tubes.
another black bag rhetoric technique - "conventional audio measurements" - whatever the poster wants to misuse to try and score points
even John doesn't seem to acknowledge that multione, DIM are AP menu items for decade(s?) now
even John doesn't seem to acknowledge that multione, DIM are AP menu items for decade(s?) now
My current project , where in one specific way I want to get the best from both type of devices, one small triode (A-class SET) driving modern SS devices( A-class SEPP) http://www.diyaudio.com/forums/pass-labs/290992-hybrid-class-retro-amp.html
Best Regards
- Status
- Not open for further replies.