I'm in between houses right now, so most of my DIY gear is in storage. I won't really be tinkering with this amp. It's just going to run and make good sound.
It is true that there is no guide pin. However, the socket is indeed keyed. The distance between pins is not uniform like octal/noval sockets. By varying the distance between pins, you create a circular pattern in which the tube can only go in one way.
After powering on with the Russian GU-50 tubes, a purple haze appeared inside the tube and I heard loud hissing in my speakers. Is this arcing?
This phenomenon happened to both channels, so it's unlikely there's a defect in the tube. They are OTK certified too, which is the highest Soviet military standard.
I also own this amplifier. The purple haze you are seeing in your tube is most likely a vacuum leak. Check this website:
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also a single ended FU50 design, they state that the tubes can be interchanged with GU50.
Google Translate
also a single ended FU50 design, they state that the tubes can be interchanged with GU50.
- Can you and old Speilbergo state specifically where you purchased your Peach from if your geographically located in the USA, and the price? Thanks.
- Is there yet a definitive mods thread for upgrade/replacement parts, and tube swapping yet for the Peach, or is this it? ( a lot of random, very random, posts aboit it...).
- Are you Peach owners going to start a definitive mods thread just for this model?
An externally hosted image should be here but it was not working when we last tested it.
The schematics of the amplifier.
I just bought this anonymous / generic / unnamed 6P1 amp that's surprisingly decent for the $99 cost (warning, power cord not included
)6P1 Class A single ended stereo tube amplifier special! - eBay (item 270488029061 end time Feb-24-10 08:00:10 PST)
With the volume control turned all the way up, head in speaker, not a hint of hum. I can't say the same for my 3.5x higher cost Little Dot III+.... which is only 1/5 the power too of the aforementioned 6P1 amp.
This little amp is driving my new-to-me Tannoy system 8 monitors, supplemented by a NHT 10" sub w/accompanying SA-2 amp x'ed over @ 75Hz, to a very reasonable and pleasing level.
I suspect there may have been a vacuum leak as well. I am trying GU-50 tubes from another USSR factory to see if there is the same problem.
I bought it on eBay, look for seller: ns_fm_transmitter. They speak decent English and response time to questions is very fast.
No mods thread yet. The 6N3 tubes are cheap to swap. The 6N1s range in price. The FU-50 shouldn't be very expensive. Other modifications should be straightforward. The modular nature of the PCBs makes modding fairly easy.
I hadn't planned on it.
That schematic is close, but it's missing the initial preamp stage with the 6N1P.
Thanks Mazuki-
Didn't see a single Sweet Peach listing from ns_fm_transmitter on their ebay store/listings.
You should start a mods thread for it I think!
Also, who can identify the make and model number of the amp in the pic? Thanks
Didn't see a single Sweet Peach listing from ns_fm_transmitter on their ebay store/listings.
You should start a mods thread for it I think!
Also, who can identify the make and model number of the amp in the pic? Thanks
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Here's the link to the eBay listing
HLLY Class A SE 13W x 2 Tube Amplifier with MM/USB DAC - eBay (item 330380779729 end time Mar-25-10 15:53:41 PDT)
As I expected, the price has gone up. I bought mine for $270 total, shipped to the US. As I expected, they actually made a loss on it. You could try driving a hard bargain on them.
I'm in between houses right now, so my DIY equipment is packed up. Maybe later this year. The amp sounds great right now!
I really really do love this site. Once I start researching something, I spend hours to days here!
The variations in the Sweet Peach are news to me. I own a good many Audio Research amps, so am very acquainted with the sound of the 6550 driven amps. I of course know of them, but I do not have personal experience of all the other drive tube's sound signatures. Since it just so happens many of the major/common output tubes are accounted for in those variations in the Little Peach, anyone in the know, feeling "talky", to convey their opinion of each amp's 'signature' they impart to the sound?
The 6N1 should be the driver tube, see my post #54
Look here:
Audio-GD Panther power amp anyone? - Head-Fi: Covering Headphones, Earphones and Portable Audio
SveinB
I was going to draw up a schematic for the Peach but I'm happy to see someone has already found one. Where did you find it siqdiz? I can't read any of the values in your image, is it available online? So far I'm still very pleased with this amp, as far as I can tell some quick mods might include replacing the 4 suspicious "WIMA" coupling caps in the input/driver stage, replacing some of the resistors in the signal path (about 6 of them) and repositioning and shielding the signal cabling (it is neatly zip tied to the power feeds from the factory
). Without a complete schematic I'm still not sure how the 6n1p driver tube is able to work effectively as the anode voltage at the socket is very low for that tube(~129vdc). With such a low voltage at the anode I figured I'd pop in one of the many 6n6p's I had in the closet. I'm sure the circuit isn't close to optimized for the 6n6p but it works and sounds very good, it has less gain than the 6n1p so its a little more relaxed, cymbals, snare drums and brass sound great. Even after hours of use, at levels loud enough to hear a room away with the shop vac running and the miter saw going the power transformer is just slightly warm to the touch, the ouput transforms never warm up.
I also noticed the price has gone up, I paid $285 shipped air mail from HLLY in China, the only listing I see now is from a different seller in China for $388 shipped. Unfortunately at this price it starts to compete with the Audioromy FU29 and Yaquin MC10l amps shipped surface.
). Without a complete schematic I'm still not sure how the 6n1p driver tube is able to work effectively as the anode voltage at the socket is very low for that tube(~129vdc). With such a low voltage at the anode I figured I'd pop in one of the many 6n6p's I had in the closet. I'm sure the circuit isn't close to optimized for the 6n6p but it works and sounds very good, it has less gain than the 6n1p so its a little more relaxed, cymbals, snare drums and brass sound great. Even after hours of use, at levels loud enough to hear a room away with the shop vac running and the miter saw going the power transformer is just slightly warm to the touch, the ouput transforms never warm up.I also noticed the price has gone up, I paid $285 shipped air mail from HLLY in China, the only listing I see now is from a different seller in China for $388 shipped. Unfortunately at this price it starts to compete with the Audioromy FU29 and Yaquin MC10l amps shipped surface.
I've seen some comparisons of the FU50 to a 300b (perhaps really only from the sellers?). Would you go so far in any way?
I was going to draw up a schematic for the Peach but I'm happy to see someone has already found one. Where did you find it siqdiz? I can't read any of the values in your image, is it available online? So far I'm still very pleased with this amp, as far as I can tell some quick mods might include replacing the 4 suspicious "WIMA" coupling caps in the input/driver stage, replacing some of the resistors in the signal path (about 6 of them) and repositioning and shielding the signal cabling (it is neatly zip tied to the power feeds from the factory
I also noticed the price has gone up, I paid $285 shipped air mail from HLLY in China, the only listing I see now is from a different seller in China for $388 shipped. Unfortunately at this price it starts to compete with the Audioromy FU29 and Yaquin MC10l amps shipped surface.
The schematics I pulled from the Xiangsheng HeiFei website (manufacturer of this amp), they also produce the Music Angel. This is the best version I could find.
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