Hi @scm - I just got my Modwright 9.0X PSU moded to use tube rectification. I am ready to try some vintage tubes. There is a white ceramic resistor right next to the tube socket. Tubes with wide bases (like the coke bottle style RCA 5R4GYs) seem to tilt the resistor a little bit. Not a lot but surely noticeable. Modwright assured me that this was not a problem - but my OCD is kicking in to high gear. What was your experience like? See pics below. https://imgpile.com/images/C3jlIl.jpg Thanks!
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@pistha All I did was roll the tube in so that it didn`t lean one way or the other. I wouldn`t worry about it one bit. Did you listen first to the Sovtek ? Just curious |
@scm - thanks. I did listen to the Sovtek. It defintely sounds more refined and there is a little more 'meat on the bone' - so to speak when compared to the SS rectifier. But I am waiting for the tonal richness and the big sound stage that Dan talks about. I hope the vintage tubes will deliver that! |
@scm - I managed to get my hands on a NOS Mullard 5AR4 - boy what a transformational difference it made! Rich tonality, clean sound and wide sound stage. @theflattire - the upgrade is worth the $. |
@pistha It`s amazing that one tube does makes that much difference. Well worth the investment of both upgrades but changing out that Sovtek tube to a vintage type 5AR4 is transformative 👍 |
Kristen did mention that the 5AR4 has the lowest forward voltage drop - I assume it just means more output DC voltage. Presumably this makes it possible for the unit to deliver the full spectrum of audio frequencies and hence sounds more dynamic. I still badly want to try the RCA Double Getter 5R4GY - they are supposed to rival the WE 274Bs. But I am still concerned about the wide base of the 5RrGY tilting one of the ceramic resistors. I got an email from Mod saying the tilt is fine and I should ptobably trust them. But in all my years of using tube gear - never have I seen any component touch each other with the exception of shielded wires. Still curious if others had similar issues with this particular tube rectification mod. Please share |
I had Dan update my PH9.0 to a 9.0XT. In my pro calibrated audio system (modest) and using a Pro-ject Xtension10 turntable with a Soundsmith Paua ES cartridge, I found that without question and in my system that for 6922/e88cc tubes, Valvo and Philips SQ miniwatt (same tubes from Heerlen plant in Holland 1960s) sound the absolute best and even better with Herbies Rx rings toward top of tube. There sound is about identical with maybe a very small dose of additional extension with the Philips SQ tubes. These are audibly very well balanced tubes with most holography, projection, texture and tone. Only Siemens tubes came close. Other tubes didn’t quite cut it and had too many shortcomings. They were Amperex Holland (7308 with surprisingly small soundstage) , Amperex JAN USA Cryo tubes ( 7308 soundstage weirdly very tall and sound a bit off) , nos Bel India E88cc ( not bad actually) nos Mullards ( not extended enough but good tone) current production Gold Lions (meh), Valvo PCC88 7v nos tubes ( similar sound to Valvo and Philips E88cc but a bit brighter and less full sounding, but still good tubes for this phono pre) and nos Philips JAN green label E88cc tubes ( dull). Alll tubes were measured near nos or better when purchased. My tube of choice for the PS is Raytheon (Japanese made 1970) 5AR4 tube. It has the smallest voltage drop and sounded the most correct vs an RCA 5r4 big bottle (way too warm) and an NOS 5ar4 Mullard that everyone raves about. The Mullard sound signature was somewhere between the rca and Raytheon but wasn’t quite extended enough. I was reaching for highs that weren’t quite there. The Raytheon was closest to solid state but with just the right amount of tube goodness. The stock Sovtek tube is a good ( slight grain) starting point but doesn’t quite deliver like the Raytheon. I could live with it and I’d still choose it over the Rca or Mullard. I suppose the Mullard would be good in an excessively bright system. The NOS RCA is simply too warm. A Herbies Rx ring for the Raytheon took it up another notch when placed toward top of tube for better focus. This is my conclusion after much experimenting with a variety of nos tubes. |
@hifi59 ...Nice write up. I recently pulled the 6922 Reflectors and put a set of Voskhod 1975 6N23P Rocket Logo SWGP Grey Shield`s in and they are going to stay put ! Highly recommended
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@scm Agree the Reflektor in the 6922 spot is not great. The top end leaves one wanting more. However, I do highly recommend the Reflektor 6C45 if you can source them. They are much better than the stock Sovtek. I ended up selling a pair to the thread starter, @ericsch, who might be able to comment on those. |
@blisshifi the tubes that were replaced were actually Reflektor 6H23N-EB`s no less. The Reflektor 6C45`s are in there already 👍 |
Reviving a bit of an old thread here, but about to send my power supply in for the T upgrade and am looking into tubes... The Philips 5R4GYS has been recommended to me as a superb replacement to the stock one that comes with the upgrade, but I can't seem to find any at a...rational price point. Anyone have any leads? Now that it's a little more widespread with adoption, maybe others have some more input on alternatives that are great as well. I saw Raytheon 5AR4, NOS Mullard 5AR4... |
