Post by CAJames on 07/13/25 at 16:02:20
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Looking forward to your impressions.Quote:
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Yes, they are user replaceable. I think it is highly unlikely the failure is related to the turntable.
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https://www.decware.com/cgi-bin/yabb22/YaBB.pl AUDIO FORUMS >> General Discussion and Support >> Did my VPI blow my Decware amp? https://www.decware.com/cgi-bin/yabb22/YaBB.pl?num=1752412441 Message started by JHC on 07/13/25 at 14:14:01 |
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Title: Did my VPI blow my Decware amp? Post by JHC on 07/13/25 at 14:14:01 I recently picked up a VPI Classic Signature. It was set up by Mat at VPI and immediately after hooking it up to my system I noticed the dreaded pop when the motor was started and stopped. This is a well known issue with VPI turntables (had I really understood how big, I might not have purchased it...). I have it hooked to a Tavish Classic phono stage and a SpaceTechLab preamp. But the odd thing was that the popping—sometimes it was more of a clicking—always sounded like it was coming from my SE84UFO. This occurred even when I turned the volume to zero on the pre AND when I switched the input. The pre has two inputs, I use the RCA for the phono state, and the XLR are empty. So I would switch to the XLR, start/stop the turntable, and I would still sometimes still hear a pop/click. Today I started up the system and the rectifier on the UFO flashed (Sophia Electric Aqua II 274B). The Sophia was still glowing so I tried it out, nothing, no sound. I swapped in my PSVane and.... nothing. No sound at all. So, wondering if I blew the fuse on the UFO, or something worse. Before I open it up and have a look I thought I would post here and see if anyone else has a similar experience. Also, I have called and emailed VPI several times this week asking for them to send me the more beefy capacitor, but they have not responded or answered the phones. To be honest, this is making me want to return the turntable and look for something else. |
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Title: Re: Did my VPI blow my Decware amp? Post by Geno on 07/13/25 at 15:15:20 Hi JHC. Sorry about the issue. You say the rectifier is still on - glows? |
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Title: Re: Did my VPI blow my Decware amp? Post by CAJames on 07/13/25 at 15:39:28 Unfortunately it seems like the Sophia Electric Aqua rectifiers have a pretty high mortality rate. I think what happened is when you turned the amp on and the rectifier flashed it blew one or both the the low value fuses under the rectifier. If the tubes glow the main fuse with the power cable is still fine. The fuses are either 0.5 or 0.25 amps, I forget which. FYI/FWIW there are two circuits in a tube amp. A high current low voltage circuit that makes the tubes glow and a high voltage low current circuit for the actual music. It is the high voltage circuit that goes through the rectifier and blew the fuses so your tubes still glow but you get no music. |
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Title: Re: Did my VPI blow my Decware amp? Post by JHC on 07/13/25 at 15:56:08 Hi James, thanks for this. Nice to know maybe it is not the turntable that cause the problem. Although I do understand those Sophia rectifiers are less than dependable. I actually have a Mullard GZ33 en route based on your reviews. Do you know if those fuses are soldered in or is it something I can swap out myself? |
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Title: Re: Did my VPI blow my Decware amp? Post by JHC on 07/13/25 at 16:00:34 To answer my own question, I found this post by Steve. I will give it a shot. https://www.decware.com/cgi-bin/yabb22/YaBB.pl?num=1655403160/1 Looks like i might need two 200mA fuses and maybe (but unlikely) one 5A fuse. Does anyone have any recommendations for good fuses? Fuse swapping was a rabbit hole I was looking to avoid.... |
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Title: Re: Did my VPI blow my Decware amp? Post by CAJames on 07/13/25 at 16:02:20 Quote:
Looking forward to your impressions.Quote:
Yes, they are user replaceable. I think it is highly unlikely the failure is related to the turntable. |
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Title: Re: Did my VPI blow my Decware amp? Post by Lon on 07/13/25 at 16:17:35 I agree with James, it's highly unlikely the turntable caused this failure. Replacing the fuse(s) is easy enough. Having the right values on hand is something I've learned to maintain. |
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Title: Re: Did my VPI blow my Decware amp? Post by JHC on 07/13/25 at 16:20:55 Thanks everyone for the help, I am feeling better about it. Are there any fuses that might work better or that people recommend? |
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Title: Re: Did my VPI blow my Decware amp? Post by CAJames on 07/13/25 at 16:31:27 Quote:
 Oh boy. "Audiophile fuse" like e.g. "Audiophile power cables" and "Audiophile ethernet" is a whole world onto itself. There are plenty of threads here about specific fuses and fuse replacements, as well as probably every other audio site. My usual recommendation is to start with ceramic fuses which only cost a little more than basic glass fuses and offer (for me, at least) a small but noticeable improvement. |
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Title: Re: Did my VPI blow my Decware amp? Post by JHC on 07/13/25 at 17:04:36 Yes, rolling fuses is something I really don't want to get into, but now the opportunity has presented itself so... I popped the bottom off and it looks like I have: 2x T200mA L250V fuses 1x 5TT6A 125V fuse According to the article by Steve, the third fuse is always 5A. Mine appears to be 6A. Should I keep that one, or swap it to 5? And, it looks like one of the 200mA fuses is blown, not all the way, but the wire has unspooled and the glass has milky streaks—I tried to take a photo but it was too blurry to see. |
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Title: Re: Did my VPI blow my Decware amp? Post by Lon on 07/13/25 at 17:25:30 If the 6 amp fuse is not blown you could leave it in place I believe, may not hurt however to replace it with a ceramic 5 Amp fuse. |
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Title: Re: Did my VPI blow my Decware amp? Post by CAJames on 07/13/25 at 17:26:16 Quote:
I would keep the one that is there. Quote:
Since you already have the amp open I would replace both 200 mA fuses. You can't always tell by looking if it is blown and much easier to replace both than open it up again IMO. |
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Title: Re: Did my VPI blow my Decware amp? Post by Sean on 07/13/25 at 17:32:54 I’m under the assumption that SE84UFOs used 3 amp fuses in the IEC spot. What does your sticker on bottom state for fuse rating? I don’t believe I’ve read about upgrading the fuses under the hood, I could be wrong about that. As stated by others the IEC fuse is a rabbit hole. Personally, I’d jump the fuse rolling and go for a SDFB…then you just go down the sluggo rabbit hole! |
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Title: Re: Did my VPI blow my Decware amp? Post by Lon on 07/13/25 at 17:40:50 Sean, the fuses discussed above are those under the chassis, not the IEC inlet main fuse. |
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Title: Re: Did my VPI blow my Decware amp? Post by Sean on 07/13/25 at 19:04:44 Thanks for clarifying Lon, every day is a school day! |
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Title: Re: Did my VPI blow my Decware amp? Post by Lon on 07/13/25 at 19:17:31 Yes, I get easily confused. . . schooling helps! :) |
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Title: Re: Did my VPI blow my Decware amp? Post by JHC on 07/17/25 at 17:28:19 Just a quick update: I installed some new ceramic fuses and got everything back up and running. The PSVane rectifier is back in while I wait for a Mullard GZ33 to arrive. Unfortunately, I think my Sophia is just past it's 30 day warranty so I will eat it on that. So put me down as someone who have had problems with the Aqua II 274b. VPI is also sending a new board and capacitor, so that should help the pop on the turntable. Thanks everyone for your help and recommendations. |
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Title: Re: Did my VPI blow my Decware amp? Post by CAJames on 07/17/25 at 17:48:22 Quote:
Sorry about the Aqua, but it sounds like you're back in business. Looking forward to your impressions of the GZ33, which FWIW, adds a "soft start" to your amp which should be easier on the tubes. |
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Title: Re: Did my VPI blow my Decware amp? Post by Lon on 07/17/25 at 17:57:59 Good news! I have a Psvane rectifier that I prefer to a NOS British rectifiers etc. that I have. . . so at least you are up and running with a good rectifier in the meantime. |
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Title: Re: Did my VPI blow my Decware amp? Post by Tony on 07/17/25 at 19:33:50 When CA James said: FWIW, adds a "soft start" to your amp which should be easier on the tubes. I realized I was not sure what that meant. Please say more about that. Thanks, Tony |
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Title: Re: Did my VPI blow my Decware amp? Post by CAJames on 07/17/25 at 21:36:19 Sitting down to explain "soft starting" a tube amp has been harder than I expected. I guess the short answer is it means the rectifier tube warms up slowly, so the current and voltage are applied gradually to the to filter capacitors and to the tube plates after they have started conducting current. But that probably raises more questions than it answers. The details of how that works and why it matters means a deeper dive into circuit theory and vacuum tube electronics than I expect you want to read or I feel like writing. |
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Title: Re: Did my VPI blow my Decware amp? Post by Lon on 07/17/25 at 21:51:22 I was going to attempt to answer as well James and you have covered it well. And probably in enough detail. I remember being puzzled when I first tried 5V4 rectifiers in my amps and then discovered the soft start feature. It's sort of cool once you know to expect it! And beneficial as well. |
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Title: Re: Did my VPI blow my Decware amp? Post by CAJames on 07/17/25 at 22:24:56 It is an imperfect analogy, but you can think of a light bulb: when they fail it is usually when you first turn it on and it is hit with full power when it is cold. Soft start would be like gradually turning up your light bulb. |
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Title: Re: Did my VPI blow my Decware amp? Post by LiquidBlue on 07/17/25 at 22:40:57 I recalled the 274b Aqua II had some sort of startup protection feature, so I had to check again. They note that the Aqua II has “New generation of spark arc suppression technology to eliminate arc possibility”. Sounds “impressive”, but I’m wondering what exactly this means? How is that different from a soft start? FWIW, I had used an Aqua II for nearly a year in my UFO25 without issue, but with current tube choices elsewhere, found I preferred the synergy of other tubes, like a Mazda GZ32, which is also an indirectly heated “soft start” tube. |
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Title: Re: Did my VPI blow my Decware amp? Post by Tony on 07/18/25 at 01:39:36 Well, that is interesting. I had a total of three 274b Aqua II and two flared out in the 300B. I put the third one in the UFO25, and it has been fine. My other tube for that amp is a Mullard GZ33, which performs and sounds excellent. I don't need another rectifier tube at the moment, but I would not go with another Aqua II if I did. |
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Title: Re: Did my VPI blow my Decware amp? Post by CAJames on 07/18/25 at 04:50:22 Quote:
Yeah, I guess it can mean whatever they want, but this is what it means to me. Arcing and/or sparking is a particular failure mode for a rectifier, caused by the tube internals breaking down. Soft start is slowly powering up the rectifier to put less stress on the tubes and the amp. "Spark arc suppression" could in theory mean soft start, or it could be some kind of reinforcement to postpone/prevent arcing, like a seismic retrofit for the rectifier (SoCal earthquake reference). If the Aqua II really has soft start you could tell by watching your amp power up, and see how long before the back VR tubes start to flash. With an indirectly heated rectifier like the GZ32 there is a several second delay before the VR tubes begin to flash. That is soft start. With a directly heated tube like the 5R4 or 5U4 they start flashing very quickly after you hit the power switch. Typically the datasheet says if the tube is directly or indirectly heated, but I haven't seen a datasheet for the Aqua. |
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Title: Re: Did my VPI blow my Decware amp? Post by JHC on 07/18/25 at 20:15:24 I contacted Sue at Sophia Electric about the blown tube and they offered to replace it although technically out of the warranty date. So that is great. More importantly, she said they will be releasing the Aqua III within "the next day or two" and that should (ideally) alleviate many of the problems. I told her what amp I had and so it seems they have heard from a lot of customers about arcing tubes. So, one question for all of you: I can get the new Aqua III OR I could get any other of their (non NOS) tubes. Are there any other Sophia tubes that people like? I was thinking of the KT88 and 6SN7 combo for my preamp. I generally have all NOS (aside from the Aqua) so this would be a change in tube strategy. Or maybe just go with the Aqua III and see how it holds up. |
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Title: Re: Did my VPI blow my Decware amp? Post by Tony on 07/18/25 at 20:48:23 That's good to hear about an Aqua III. I'm not in the market, so that it won't affect me. Still, it is good to see them acknowledging that there was a problem with the Aqua II and they moved on to III. Since it's not my dime to risk, I'd be curious about your take on an Aqua III. In any case, good luck and choose a good one. |
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Title: Re: Did my VPI blow my Decware amp? Post by CAJames on 07/18/25 at 21:01:11 My 2 centavos is I'd try the Aqua III. I wouldn't trade NOS for new production Chinese in any event, and you like the Aqua II so I'd say stick with what you know you like, and you may have better luck with the new version. But that is JMO/FWIW/YMMV and all that. |
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Title: Re: Did my VPI blow my Decware amp? Post by Lon on 07/18/25 at 21:14:36 In your shoes as you like the II I would go for the III. These are Chinese tubes designed for Sophia and I have had better luck with them than many here. . . and the II really DO sound great. I have had even better luck in some ways with a few other Chinese tubes, to whit the Psvane Collector Black Treasure 274B-Z and the Linlai 274B-D Dream Series rectifier. The former is very classic and warm sounding, the latter very dynamic and clear. And both have been very very dependable in my SEWE300B and Zen clone amp and CSP3 preamp. As a possible reference I would say that the II sounds in between these two in character. |
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