Chomping at the bit . . .

[anarchist]

To bring this back to VRD's Verses anything else - you may well - under test conditions, show that no-one can pick them out from a Yamaha surround sound amp operating in 2 channel mode - but that does not mean that in the quiet of one's own home this would be true.

See. In my first post on this, I said someone would complain about the validity of the test. Thanks Max.

For the record, I believe the "VRD's" could be picked out from a Yamaha surround sound amp (given a specific set of conditions) - but that does not mean that in the quiet of one's own home this would be true. It also doesn't mean it wouldn't be true.

Tests are most interesting when folks are asked to write their observations of what they are hearing when they are listening to it - in addition to "ranking" the amps. It is amazing how folks (who believe they are comparing one amp against another) will hear the same amplifier playing the same music and alternate being claiming it sounds incredible and claiming it is the worst thing ever. They will identify it as lush one minute and then identify it as cold and sterile while listening to it again a minute later.

Nerves or psycho-acoustics?

[maxg]

To bring this back to VRD's Verses anything else - you may well - under test conditions, show that no-one can pick them out from a Yamaha surround sound amp operating in 2 channel mode - but that does not mean that in the quiet of one's own home this would be true.

See. In my first post on this, I said someone would complain about the validity of the test. Thanks Max.

For the record, I believe the "VRD's" could be picked out from a Yamaha surround sound amp (given a specific set of conditions) - but that does not mean that in the quiet of one's own home this would be true. It also doesn't mean it wouldn't be true.

Tests are most interesting when folks are asked to write their observations of what they are hearing when they are listening to it - in addition to "ranking" the amps. It is amazing how folks (who believe they are comparing one amp against another) will hear the same amplifier playing the same music and alternate being claiming it sounds incredible and claiming it is the worst thing ever. They will identify it as lush one minute and then identify it as cold and sterile while listening to it again a minute later.

Nerves or psycho-acoustics?

Sorry Robert - testing is something I have been thinking about for a while and you just gave me the opportunity to voice my thoughts.

Nerves or psycho-acoustics? Probably a combination. Group pressure can come into play too - What? You can't hear the difference? Are you deaf? etc.etc.

Having said that - I have attended a Nordost demonstration that proved to me you can convince anyone of anything when it comes to sound. 9 interconnects - from cheap computer units to Valhala's. Each one a huge leap forwards from the last. Dramatic differences - wow.

But - at the end of the test - we went back from Valhala's to the computer connections. Yes we still heard differences - but somehow the differences we heard going from one cable up to the next one in the range did not appear to be cumulative. If the Valhala appeared to be, say 10% better than the next one down it also appeared to be 10% better than the computer cable. The next one down (can't remember the name) also sounded 10% better than the computer cable but 10% worse than the Valhala.

Never could get that one explained.

Very very clever presentation.

[anarchist]

Good posts Mark & Max,

I agree... for the most part. I just believe you can structure the tests - go past the strictly AB testing - and use additional criteria to add some meaning or validation to the tests.

In the PC world, we assess usability in a variety of manners - the simple and most common way is to stick some guy in front of a screen and then calculate how long it takes him to complete a task on different systems. This like your standard double-blind test provides some objective data but is by no means conclusive.

In the PC world, you dive further into usability via methods that observe human behavior and correlate it to the objective measurements. I suggest similar methods can be applied to audio.

In the end, though, yes, I don't believe objective measurements can completely validate or invalidate subjective opinions. Subjective opinions, however, are highly suspect in predicting whether others will derive the same enjoyment or share the same beliefs.

[NOSValves]

Sheltie,

I propose psycho-acoustics plays a large role in what people perceive they hear. Yes, I suggest in a double-blind test, even your golden-ears would have a difficult time picking out one good tube amp from another good tube amp. Lots of people have claimed they can do this or that... tests haven't borne out those claims.

Your sensitivity to statements about VRD's is unfounded and makes little sense. VRD's are modded Dynaco's per Craigs own mouth. Are they Dynaco Mark III's? No. Will they sound like stock Dynaco Mark III's? No. I submit, however, under certain conditions, it would be extremely difficult to reliably identify one from the other. The only argument that can be made is they are a better mod than other mods and only someone who has listened to all of the available mods and compared them could answer that definitively (and even then I question the repeatability of their choice in a double-blind).

I have no doubt that Craigs implementation is a good one. Hell, I entertained the idea of buying a set on more than one occasion until I was able to get the deal I got on my Mark III's and frankly, I enjoyed modifying them myself so I am glad things played out the way they did. For someone interested in a turnkey solution, Craigs amps are certainly worthy.

Lastly, I wasn't interested in an argument about VRD's; substitute whatever you like in there. My point was people claim they can hear this and that and attempt to make subjective statements appear to be objective evidence; I merely suggest objective evidence seems to contradict their claims.

Hell, to make it even more interesting, we could have mas treat the room, Dr. Who measure everything, and do all listening tests on Dean's Jubilees while rolling the music I choose. Still think you will be able to identify one amp vs another? Think you will be able to pick out "your" amp? Think you will be able to pick out the "VRD's?" What about the Chinese amp? Maybe you or some other golden-eared audiophile with 100% sound retention and perfect memory could do it... but I would have to see it to believe it.

MY AMPLIFIERS ARE NOT MODIFIED DYNACOS !!!!!!!!!!!!!!!!!!!!!!! I HAVE NEVER STATED THAT. If you can stuff all that is in a VRD in a Dynaco chassis then have at it. The only thing they have in common with a Dynaco is the same winding "technique" was used on the output iron and the operating voltage of the output tubes is within 10 to 15%. The transformers could not even be used as a direct replacement for a dynaco amp if the mating amp had Dynaco Iron the two amps would not timber match or voltage match.

QUIT POSTING ABOUT THINGS YOU KNOW NOTHING ABOUT!!!!!!!!!!!!!

I can modify a Dynaco to be similar to a VRD but it will never be a VRD even if VRD iron was used in the project.

Craig

While the cats away the mice will play. One hour on this forum and I'm ready to just stop logging in. So many back stabbers around here. Sure am glad at least 90% of the population are reasonably good folks or I would just stop posting.

[meagain]

Welcome Home! [:#]

[NOSValves]

Thanks how are your amps doing?.................man am I asking for trouble. You should call me before I've been back in action for a while [] I may not even scream at you LOL!!!!!!!!

Craig

[anarchist]

MY AMPLIFIERS ARE NOT MODIFIED DYNACOS !!!!!!!!!!!!!!!!!!!!!!! I HAVE NEVER STATED THAT. If you can stuff all that is in a VRD in a Dynaco chassis then have at it. The only thing they have in common with a Dynaco is the same winding "technique" was used on the output iron and the operating voltage of the output tubes is within 10 to 15%. The transformers could not even be used as a direct replacement for a dynaco amp if the mating amp had Dynaco Iron the two amps would not timber match or voltage match.

QUIT POSTING ABOUT THINGS YOU KNOW NOTHING ABOUT!!!!!!!!!!!!!

I can modify a Dynaco to be similar to a VRD but it will never be a VRD even if VRD iron was used in the project.

So sensitive.

What was the basis for your amplifiers?

You stated to me and to others (years ago and posts exist) the VRD's were a result of the narrow confines of the Dynaco chassis limiting your ability to increase the power supply and experiment with other changes.

So you take a circuit, hot rod it, beef up the power supply, add a triode switch, spec different transformers and place them in a new chassis. Is it a Dynaco Mark III? No. Is it an entirely new creation? I don't think so and you have said as much.

Its a good amplifier. Nothing to be feeling sensitive about.

It would be nice if people didn't allow emotion to over-rule logic and irresponsibly launch claims of backstabbing anytime anyone with a different viewpoint voiced it. It would be nice to hear what people really think about equipment without them being afraid to state so; everything in audio has good qualities and negative qualities.

Amplification doesn't really interest me that much anyway. I am more interested in preamp design at this point and the merits of a 5687 tube vs a 12b4a. Scratch built circuits, of course.

[NOSValves]

It would be nice if folks that did not have a clue WTF they were talking about would simply shut the hell up. You fit the bill perfectly.

[mike stehr]

"Amplification doesn't really interest me that much anyway. I am more interested in preamp design at this point and the merits of a 5687 tube vs a 12b4a. Scratch built circuits, of course."

Well, find a good regulated tube DC power supply, build yourself a breadboard jig and get on it.....

I've tried simple RC coupled linestage type circuits with both those tubes. I had noise problems with the 5687, and didn't feel like spending the money for more of them, so I kinda bagged that.

The 12B4A is a interesting one. But they can be rather microphonic like a 6SN7, so buy a bunch. They are cheap. The GE JAN and other JAN brands are probably better with respect to microphonics.

12B4A would probably benefit most from heating with a DC supply of some sort. They will need a good clean PS as well. (As with any pre-amps/linestages.)

I've been wanting to follow through the 12B4A linestage project, but have been sidetracked with other amp projects and a B&C 12CX/B coaxial project......too many projects......

[NOSValves]

Amplification doesn't really interest me that much anyway. I am more interested in preamp design at this point and the merits of a 5687 tube vs a 12b4a. Scratch built circuits, of course.

I see you now best buddies with Douglas.................you two should get along gingerly.

[anarchist]

As far as not knowing what I am talking about, it is pretty simple and maybe you should pay attention to yourself.

Oh and please spend a few hours finding posts where I have professed to
designing something new, revolutionary or that I'm a master designer???

In fact when asked to describe my circuits I always say they are stolen
from various vintage designs coupled with a modern stiff power supply.

You said it, not me.

[garymd]

Gary has Craig's original hot rods, and has heard VRDs, and even then it is hard to say the MKiiis are the same thing.

Dave,

FYI - I sold the MkIIIs to Rich (RPlace) about 2-3 years ago and bought cherry VRDs. As nice as those hot-rodded MkIIIs sound, they can't compare to the VRDs IMO. Those are some of the best sounding MkIIIs around too.

[anarchist]

I see you now best buddies with Douglas.................you two should get along gingerly.

I think your own words are the best admonishment I could offer given I don't know who Douglas is.

It would be nice if folks that did not have a clue WTF they were

talking about would simply shut the hell up.

I am so done with you Craig. Go 'bout your business unless you can be nice and say something useful about preamp design.

[NOSValves]

I do go about MY business. You should do the same.