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Now that I am getting VERY close to that "straight wire with gain" thing, with a two-tube-stage preamp no less, I made some further mods to get it even closer. The tedious process of comparing a new mod vs. no preamp in the chain continued endlessly. In the end, I ended up adding FT-1 Russian teflon caps to the large VCap teflon output caps. It's kind of counter-intuitive, but even a great cap like VCap can benefit from a small teflon bypass as the cap size increases. Where small teflon caps seem to really thrive is bypassing power supply electrolytics, and I added some more FT-1 teflon caps to various PS electrolytics. These changes ended up giving me that last 3% of extreme treble air, extension, and coherent sweetness. I'm still surprised when improving the high frequency seems to enhance bass definition, but that happened as well once again
In the end, I ended up adding FT-1 Russian teflon caps to the large VCap teflon output caps. It's kind of counter-intuitive, but even a great cap like VCap can benefit from a small teflon bypass as the cap size increases. Where small teflon caps seem to really thrive is bypassing power supply electrolytics, and I added some more FT-1 teflon caps to various PS electrolytics.
I have been playing with the GG, and while I was happy it already had the Goldpoint stepped attenuator, Grayhill switch, Auricap upgrade, and solid core silver wire in teflon, it still sounded like I inserted a tube preamp into my system and what that implies Before GG fans get upset, do understand that my previous system did NOT even use a preamp. I was able to tweak the gain stages and my audio PC's digital signal output to do fine without a preamp. When I got the GG, I simply placed it in my system, so the setup now had one more active component and another run of (same) interconnects. And yes, I could hear them.. What was most bothersome was what I perceived as fuzzy bloom overlaying everything and slightly "puffy" bass and loss of absolute transparency of resolution, especially in the upper-midrange. I am sure someone replacing a less-well-engineered preamp with GG would be delighted by it, but I'm comparing it to the proverbial "no preamp."Luckily, a lot of the character I heard, I recognized from my capacitor-rolling experience with Auricaps. I then replaced the Auricap output caps (which was already an upgrade from stock caps) with VH Audio Teflon capacitors of the same value. Color me impressed! Fuzz turned into resolution,......
Could I implement the shunt attenuator mod in an Alps volume control in my Supratek Preamp? Or this mod would require discrete resistors?I remember that in a Reference Line preamplifier I had, it originally had an Alps volume control. Wasn''t this a shunt application? Thanks!
Check out opticoupler volume control for your GG pre.It's transparency is evident. It makes a fine pre VERY fine!Best, Don
I just rewired the volume pot in my TS GG pramp from stock series, to shunt, effectively removing the pot from the signal path. The preamp does sound very different(still evaluating).It seems so very obvious to do this mod, I have to question why would any body design a preamp any other way?What is the possible downside?Why would anyone ever bother with expensive discrete resistor attenuators?What am I missing?So it goes.........
Which opto-coupler did you use? I do have a LDR passive (Eva), and yes its transparency is awesome, but the volume control's increments are not fine enough for my needs. Granted, I run high-ish sensitivity system (96 dB sensitive).
Jon,If you want it to sing....you need to do the following:bypass all the switching and the volume control.....simply wire a 10K resistor from one of the input jacks to the grid of the first tube....and from the same spot run a wire to the pot which will just be used as a shunt to ground. Super way better sound.Change the rectifying diodes to some IXYS soft recovery types. Bypass the power supply with serious caps.Remove the fuse.Damp the tubes.Change those output caps. The one I had here had Axion 1uf caps....film and foil polyprops....not bad...did not try any others.Use two of them dual mono. The last tube shares both channels....this is a no no in my book. I did not listen dual mono.....even one with the above mods was pretty killer. Certainly, with mods, the best preamp for the money I have ever heard.....stock it is OK at best......Ric
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