I am pissed, disappointed depressed and my ego is a size of a brains or an average audio-Moron.

For a last number of days/weeks I was truing to do something extremely simple and still I had failed with a disasters fiasco. All that I need was some kind of vacuum tube buffer that would have no-gain of a very low gain and that would be sonically completely transparent. Believe me or not but I was not able to make such a stage (of whatever radical designs I trued) that would deliver a level of transparency that my playback would demand.

So,

I am depressed and semi-suicidal…

Anyhow,

if any could point to me to some kind of no-gain of a very low gain buffer then please let me know. To whoever lead me to a direction of line-level transparency I promise to make a reword.  Nope it would not be a first born but rather as a compilation/s of my selected musical peaces.

Rgs,
Romy the Cat

building a preamp based in the same tube you're using on the Melquiades and results aren't what you expected. Have you?
I wish I knew how to do it, I'd love receiving a compilation of your favourite music. Anyway, why do you think you'll get better results with no gain or very low gain? As I see it the problem might be that the tubes you've tried aren't completely lineal, so they introduce their own sonic flaws to the signal. Maybe all you need is trying a simple approach regardless of gain, and doing it with the most lineal device you can find, perhaps an opamp or a RF tube. Probably this makes little sense or is too complicated to implement, but you know, ignorance is dared.
The other way to go might be using the buffer section of a known preamp that you like, it might not be completely transparent but would introduce modifications which go in a known and liked direction. Maybe Lamm's buffer is all you need.

Rgrds,

AJ

I have no “apparent aversion” to anything at this point and I would accept absolutely anything that would deliver a result, no mater how crazy it would be. I do not talk even about the X-factors or about anything “kinky” but only about a plane transparency.

You know this state whet a line level device introduce no sound and an introduction of it into a signal path change absolutely nothing? I mean not “almost nothing” or “practically nothing” but a situation when there is absolutely no differences between driving 150K Melquiades with for instance 47R of Bidat source and an introduction a unity gain buffer between the Bidat and Melquiades has no any kind effect to sound. Whatever I trued, no mater how aggressive it was design-wise or how well it was built was able screw the source’s sound. Practically it is horrifying in the very tiny world of lower bass’ tonal and dynamic discrimination.  In fact, it was not only there but pretty much everywhere and it always filtered out something.

Certainly I did try a number of different topologies and power supply methods, in including the complete Melquiades input stage running it into rolled-off sensitively of load or killing it gain with a feedback. The problem with all of this was that it didn’t juts deliver a satisfactory result but that is delivered a result that was not even close to the level where any serious conversation might be even started.

I juts do not want to continue on this zombie-research, building the different buffers and keep convincing myself that it was no transparent enough. I know that I act almost like a woman during PMS but so far I have managed to bult a strong prejudges and fear that all of buffers are not transparent enough.

The Cat

Brian Clark wrote:

A buffer …. loses information in the process

Romy the Cat wrote:

 ....to plug the cables? :-)

Brian Clark wrote: A buffer …. loses information in the process This <U><STRONG>is</STRONG></U> execlty what I would like to challenge.

guy sergeant wrote:

.... there will inevitably be some degradation of the sound with whatever switch you use and with whatever buffer you choose. I find that the losses incurred there are far less than the differences in quality between various recordings.

Alex,

yes, the passive linestages (resistors) tend to be more transparent then active stages but it is only in the case when a passive line stage (attenuator) sits right next to the grid of your input tube. As long as a passive linestage begins to drive a cable everything go to toilet with dynamic and LF dying first. My usual comment about it was something like this: a perceived quality of a passive linestage could be determined by the misery of system’s LF section – the worst LF capacity of playback the better apparent quality of a passive linestage. Anyhow, I looking for only an active stage.

Rgs the Cat

cv wrote:

I wonder if it is the reactive components (blocking caps etc) that are to blame here, seeing as much of the problem is in the lower bass.

Look, the output of Bidat and a SS buffer that being bult for me now are direct coupled and they do “a perfect” bass. The buffers that I tried were capacitance coupled and all of them delivered identical (regardless of topology) worsening of bass. I trued the transformer coupled (amorphous Lunhale) and I lost bass as well, differently then with caps but still it was a sever lost of amplitude. The capacitors did not loose amplitude but they degenerated the quality and the definition of bass.  I did use various capacitors in there but this game I played log time ago and I know that the caps I use all were the best in existence (the same the I used in Melquiades coupling).

So, if to make a presumption that the output capacitor of the buffers was a guilty party, and this is the very same cup that is so phenomenally-good couple the Melquiades’ inner-stages then where would it lead us? Does it mean that in the “Super Melquiades” when I intend to use the same cap in the LF channel this cap will be the weakest element?  (Thanks God I have resolved the problem with the transformer). Would be a good idea do not use those caps in there but to look at something else? Perhaps a very large electrolytic cap will do better as a coupleling cap in the sub 100Hz amplifier or perhaps the back-to back electrolytics with a negative bias? Yes, theoretically in that location 6uF introduce a second order roll-off at the fraction of a hertz but perhaps there is something else in there, considering that Melquiades pumps unspeakably low bass? Perhaps it is about the shaking the dielectric or something like this?

Any thoughts on it?
The Cat

Romy the Cat wrote:

the passive linestages (resistors)tend to be more transparent then active stages but it is only in the case when a passive line stage (attenuator) sits right next to the grid of your input tube. As long as a passive linestage begins to drive a cable everything go to toilet with dynamic and LF dying first.

Brian Clark wrote:

Have you experimented with transformer attenuators Romy?

First I did not see any transformers that can handle LF all the way down (beside ET but they are out of the game). I made my experiments in past with Lamm’s SET and was not able find any magnetics that can handle the LM2’s bass and now,  with the Melquiades, the result I sure would be even less satisfying.

Second, if we even presume that a transformer-attenuator is transparent enough (that feel will not be a case) then still the cables, switched; DCRs of primary and all the rest things are driven by the output stages of the sources. Some of them have quite high Rout. I believe that a good buffer with ultra low output impedance (I still do not have it) would be way better alternative from a perspective of noise, driveabilety and dynamics.

Still, my observations on the subject of transformer-attenuators are not based on my practical experiences as I always thought (perhaps arrogantly) that transformer-attenuators would be good enough only for a playback with those little ported monitors of 89dB sensitivity that are having the silk done tweeter… :-)

The Cat

Romy the Cat wrote:

cv wrote: I wonder if it is the reactive components (blocking caps etc) that are to blame here, seeing as much of the problem is in the lower bass. Chris, what you said made me to think. Look, the output of Bidat and a SS buffer that being bult for me now are direct coupled and they do “a perfect” bass. The buffers that I tried were capacitance coupled and all of them delivered identical (regardless of topology) worsening of bass. I trued the transformer coupled (amorphous Lunhale) and I lost bass as well, differently then with caps but still it was a sever lost of amplitude. The capacitors did not loose amplitude but they degenerated the quality and the definition of bass.  I did use various capacitors in there but this game I played log time ago and I know that the caps I use all were the best in existence (the same the I used in Melquiades coupling). So, if to make a presumption that the output capacitor of the buffers was a guilty party, and this is the very same cup that is so phenomenally-good couple the Melquiades’ inner-stages then where would it lead us? Does it mean that in the “Super Melquiades” when I intend to use the same cap in the LF channel this cap will be the weakest element?  (Thanks God I have resolved the problem with the transformer). Would be a good idea do not use those caps in there but to look at something else? Perhaps a very large electrolytic cap will do better as a coupleling cap in the sub 100Hz amplifier or perhaps the back-to back electrolytics with a negative bias? Yes, theoretically in that location 6uF introduce a second order roll-off at the fraction of a hertz but perhaps there is something else in there, considering that Melquiades pumps unspeakably low bass? Perhaps it is about the shaking the dielectric or something like this? Any thoughts on it? The Cat

Romy the Cat wrote:

All that I need was some kind of vacuum tube buffer that would have no-gain of a very low gain and that would be sonically completely transparent.

Thorsten wrote:

Even a pair of RCA Jacks and a wire inbetween is not transparent.

Paul, I clearly have no idea; I am purely fishing in here.

Regarding use of feedback in my buffer there was an interesting experience with it. Among the buffers that I tried there was two that used feedback: one was a an exact replica of Melquiades input stage with a loop to kill it’s gain and another was a current-biased anode follower. Both feedback buffers sounded worth among all other buffers that I tried. 

Interesting that when I used the Melquiades input stage (with no feedback) as a buffer and reduced a sensitivity of the Melquiades power amp then I had a certain Result (not perfect result but just a Result). However, when I removed the voltage devider form the power amp and reduced the buffer’s gain via introducing of a feedback to the buffer then that Result was divided by 1000 quality-wise. The sound was completely killed and I did not even anticipated how bad it would be.

I have to note that I have no opinion of agenda about benefits of feedback and do know well performing equipment that use feedback and sound perfectly fine. However in my case the feedback was a complete sonic humiliation…

The caT