Cree introduced silicon carbide Schottky diodes a couple of years ago. The 1st generation 1200 PIV parts were costly. Quite recently, Cree introduced a 2nd generation of parts, with much more attractive prices. The Mouser catalog page is here. Cree part # C4D02120A is 1200 PIV/2 A. and Cree part # C3D02060A is 600 PIV/2A.
I can hear slight differences in GZ34s. I have one in my Tubelab SSE and had one in my preamp for the last 5 years or so. I have had 2 recent production tubes give out and then bought a couple Mullards, an RCA and a NOS Japanese GZ34 when I won ebay auctions for a reasonable price, under $50, some much less. For me, it was durability rather than sound quality that made me feel it was worth it. Also, I thought the prices would go up since I bought them, and they have... seems like some tube stashes are going to be worth a fortune in the future.
Hi, just a few words on the subject of not measurable audio.
There are too many parameters to be processed (like phase cohesion, frequency dependent intermingling of sounds) for an engeneer to put up a practical recording or reinforcement system. It's to this date still done by ears only.
In the late 80-ies I had a small studio equipped for demos, nothing too fancy. When putting up mikes around a combo of three musicians, I had to listen very closely to the monitors for the outcome of the placement. Moving one mike an inch could make an instrument loose its character for a big deal. Perhaps it's in catching the basic frequencies without loosing too much of the overtones. Funny thing is that the most linear mikes (for test equipment) were not best capable of doing so.
With regard to making good recordings I must pay respect to Rudy van Gelder who's work from the 1950s era is still superior to much of the modern stuff, despite modern digital equipment with superior s/n ratio.
Me too, I'm a believer in science but there's a lot to be understood before we can safely make asumptions about even trivial things. For instance, there's a model for loudspeakers but not until 1970.
I believe. When I was in Akiba recently, I found tube shops selling merchandise that only God could afford......
How indeed can they? But they do to me. Pop in a Sovtek 5U4G and then some other NOS one.
Here is the catch. Do this in a single ended amp. It's audible. Even more so with an efficient fullrange driver. Basically anything you do is audible.
Mind you I'm not advocating paying absurd amounts or any kind of premium at all for that matter. There are plenty NOS damper diode tubes. The only drawback is you need to use 2. Or one if you combine a single damper diode with a solid state rectifier bridge. That is the advantage diy'ers have. And as Eli says you can use the HV Schottkey. Or even the 1N4007 with a RRSF or with chokes in the secondaries of the power transformers as used by Silbatone.
Last edited:
Well, some things can be explained if you are willing to believe in their existance. I'm not hinting at an afterlife but at a simple yet understandable nature of things.
For instance sound reproduction.
Waves travel through air and will finally be extinguished, the higher the frequency the sooner*. Close to your loudspeakers you'll hear more detail than at 3m. Turning up the volume will activate room resonance which was benign at low levels. As a result you again loose some of the musical detail.
For instance sound reproduction.
Waves travel through air and will finally be extinguished, the higher the frequency the sooner*. Close to your loudspeakers you'll hear more detail than at 3m. Turning up the volume will activate room resonance which was benign at low levels. As a result you again loose some of the musical detail.
Last edited:
I've got a fair number of vintage English GZ34 in service, and the one thing I will say about them is that they are reliable in way that no current production GZ34/5AR4 is. No failures at all in 15yrs.
Better regulation under varying loads and less forward drop than current production JJ, Sovtek or Shuguang 5AR4..
I hear no difference in performance attributable to brand or vintage of these tubes. (Reasonably well designed regulated supplies)
And I definitely couldn't afford to buy them today... FWIW..
I have sold most of mine for tidy profits and now only use cheap tv tubes.
I wanted to know what facts your claim ("to some extent audible differences are measurable", "not all can be explained by measurement") was based on but now it's clear that there is no such fact.
In a typical SE amp the PSU is more part of the audio circuit than it is with a P-P amp. The rectifier characteristics might make a change to the PSU output impedance and/or (for PSU with chokes) the amount of subsonic resonance damping. Combine this with the relatively low amounts of global feedback often used in SE and a small effect is not that surprising. A bit of audiophile exaggeration then turns it into a major obvious effect.Bas Horneman said:
This is not to disagree with others (e.g. SY) who say that it should not be audible. I agree with them, which is why I would only use SE in a radio set and not for listening to music.
Just to explain a bit further, a rectifier has (roughly speaking) a typical 'on' resistance. In a PSU this gets (roughly) multiplied by the duty ratio - maybe 5:1 for cap input and 1:1 for choke input? Also need to add in the secondary resistance and reflected primary resistance, also scaled by the duty ratio. You can then regard this as the output resistance of a DC voltage source feeding the first PSU cap. There is a slight complication involving the value of the first cap giving an equivalent resistance too. Anyway, you can then calculate (or model) the behaviour of the PSU as an LCR circuit. The PSU output impedance is directly in series with the OPT primary for an SE output. Remember that we are interested in frequencies from above 20kHz down to below 1Hz. We can't hear 1Hz, but musical phrasing (i.e. the signal envelope) is down in that region.
I wanted to know what facts your claim ("to some extent audible differences are measurable", "not all can be explained by measurement") was based on but now it's clear that there is no such fact.
Sorry man, I'm not in for a game of words.
If you have something to share let us know...
I dislike expensive tubes. I dislike cheap tubes too. Tubes should be medium priced, you don't treat them like crap nor like jewelry. I have a NOS Mullard GZ34, it's been sitting in a drawer for years; I also have a Full Music 6SL7 which sells for stupid money (I got it for free). Suffers the same fate as the Mullards. Recently, I could have bought (locally) some metal base EL34's and GZ34's for little money (about 30 euros each) but I didn't because I knew I wouldn't use them. I dislike speculation. I dislike bankers and treasure hunters.
DF96: how come > 20KHz is not of interest? Reading M Jones book on tube amps I got the impression HF oscillation can come from a ringing power supply, originating from high current cut off by semi conductors in the bridge. From a less steap conduction angle (if I recall correctly) valve rectifiers produce less 'sput' on the HT.
RVG is really good at horn recordings on those Blue Note sides, gobs of presence and dynamics, but his piano recordings are dismal, too hot, clippy, bangy and no "bloom." Let's not worship too much. I can think of many modern piano recordings that can sound better. Even among his contemporaries (pun intended), I would prefer Roy Dununn from the Contemporary label, great balance and a wonderful golden glow to the sound. Not all old things are better.
wow. can you hear resistors too?
Here, let me save you some time...
me: you must be deaf
you: you are imagining things
me: you have poor equipment
you: you are delusional and need to do a double blind test
me: I don't need testing, it's clear as day.
ok, hopefully that covers it, have a nice day.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.