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I recently made a preamp change from a CJ that used a single 6922 to a Von Gaylord that uses stereo 6SN7 tubes, and in general, I'm very happy with the change. The VG is significantly more dynamic with better bass, and good air in the high end. Probably the only area in which the CJ may have held a (very) slight edge was in a possibly more holographic soundstage presentation, and I suspect that a tube upgrade at some point may help there. Current tubes are green letter 1960 Sylvania 6SN7 GTB. Any suggestions for tubes that may offer a deeper, more holographic soundstage presentation? Real world offerings, please.
Lots of great 6SN7s out there.
In terms of imaging and sound staging, my current favourite are the RCA VT-231 grey glass. Still very common and reasonably priced. The RCA 6SN7 GT are similar.
There are certainly better Sylvania's than what you are using now, for imaging I would try the Sylvania VT-231 or other bottom getter versions including the three hole plate "bad boys".
The National Union black glass are nice as well. The Russian hole plate 1578 have a huge soundstage.
Enjoy the Roll!
Just some advise.
Your preamp has 30db of gain.
Rather, you need an impedance matching zero gain attenuator.
With this preamp, an input signal of 120mV is amplified to a 2V output (no phono stage) and you will be playing this from a standard digital source (or a stand alone phono preamp). Therefore you will be taking a 2v signal, attenuating it with a potentiometer or resistors to 9mV and then amplifying it back up to 150mV to drive the input of your amp. A full 2v input would result in potentially +30 volts output. This is fine if you have an amp that needs 20v to get to full power, but there are zero commercial amps set up like this.
Before you head down the 6SN7 tube flipping road and end up with some "VT-231 June 1946 SuperTubes With Hand Applied Crome Dome Super Bad Boys Platinum Grade Matched" tubes that the tube merchants push, just try an autoformer volume control (attenuator). You will be really really surprised.
It's been so many years now that everyone expected to be using a preamp and an amplifier. But maybe the whole idea of a "preamp" needs to be updated in a world where a 2v line signal is normal, and the only other need for gain is a phono stage.
The word "preamp" literally means "pre" "amplification", but take away the need for gain and you get some kind of switching and a volume control. Maybe not even the switching if your DAC is the only input, and no volume control needed if the volume control is in software. No need for buffer even if your DAC is driving a tube amp.
I see loads of threads asking "what do I do about my extra gain" here and elsewhere, but it seems that many are still reluctant to move on from the idea of a preamp. Many say "the tubes add warmth" or something similar, but in that case the tubes should surely be in the amplifier?
Preamps live on but in many cases it's hard to see why or what they're doing that's useful.
I have digital sources, but with my own amps, I have need of some additional gain. Not a lot, but some. I happen to have a buffer linestage, and while it works quite well, the amps all appreciate a wee bit more signal input.
Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.
There was a period of time after I removed the CJ from my system that I just ran the output from the Directstream Jr straight into the Antares. Yes, it sounded good, but installing the VG lent substantially more "weight" to certain instruments, most notably a piano, and even at lower volumes. The VG made all the difference there. I have never before had my system reproduce lower frequencies with that kind of authority, even with the current Sylvania tubes, so I consider the preamp a worthwhile investment. As always, ymmv.
"Unity gain" is (IMO) the key, when only digital sources are a factor. The control center can be either buffered or passive. While passive control centers can work well, they are inflexible. Short, low, capacitance cabling is a must. JMO, a highly transparent buffered control center is frequently the "best" choice.
As you stated, "vinyl" complicates the situation. Yes, I have a substantial investment in analog records and the associated equipment.
For its Passive and buffered modes. In buffer mode it uses a single 6SN7 tube. This unit is unity gain and all my sources have enough gain where the Saga doesn't run out of gas. My phono preamp has enough gain in MC mode so I can still play my LP's loud, that was my only concern when I first got the Saga. I still have never maxed out the volume control on it which is a multiple Relay/Resistor volume control.
This Saga Plus is most transparent controller/preamp buffer I have ever had in my system and that's using it in buffer mode where tube is used. It is even more transparent than the BAT VK-30 preamp I had. The only change I did to the Saga was changed out the Wima coupling caps and put in Jantzen Supreme Z caps. That one change made it even better sounding and more transparent. It also has quite a few inputs that I can connect all my Sources. I have no desire to go back to a regular preamp now that I know what I have been missing. :)
That's all. Would be nice if it also had the DAC built in, but as long as technology keeps changing that mix, it is not completely practical.
I'm not a holography expert, but nothing is more transparent than the EF86 in triode mode.
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