Yesterday I received my latest addition to my SET collection, a eBay hong-kong SUN SV-2A3 clone. The amplifier was purchased through eBay end of January and shipped to Holland with surface mail. The amplifier was bomb-proof packaged, a big thumbs up for the seller.
Before powering the device up I opened it up to check the internals, it's nice to see grounding and a fuse. I also removed the transformer covers to check what's lurking underneath them
. The transformers are not branded, but by the looks of them they are quite well produced. They have been painted with a bitumen like substance. I also like the fact that each transformer is in its own enclosure. The circuitboard is simple with the traces wide apart from eachother, the 2a3 tube sockets are ceramic. The other sockets are plastic. A nice touch is the bias points are reachable without opening the enclosure, they are located between the 2 2a3 tubes.
I never had a tube amplifier before with a tube rectifier so I wasn't sure what to expect. My speakers are ~95dB/w horns. After the amplifier was turned on I put my ear against the speaker to find out if there is any humm. During the first few minutes there was a little humm/hiss, but after about 3 minutes the speakers were dead silent. Also the power transformer isn't vibrating.
It's way too soon to make any comments on the sound quality of the device; i've been watching TV with the 2a3 amplifier, sounds good. Comparing to my Sweet Peach FU50 amp, the bass doesn't go as deep, but this is just an early observation. Once the tubes are burned in I can do a full review on the sound.
The tubes:
2x Shuguang 2a3b tubes
2x 6N8P pre tubes
1x 5Z3P rectifier tube.
Before powering the device up I opened it up to check the internals, it's nice to see grounding and a fuse. I also removed the transformer covers to check what's lurking underneath them
. The transformers are not branded, but by the looks of them they are quite well produced. They have been painted with a bitumen like substance. I also like the fact that each transformer is in its own enclosure. The circuitboard is simple with the traces wide apart from eachother, the 2a3 tube sockets are ceramic. The other sockets are plastic. A nice touch is the bias points are reachable without opening the enclosure, they are located between the 2 2a3 tubes.I never had a tube amplifier before with a tube rectifier so I wasn't sure what to expect. My speakers are ~95dB/w horns. After the amplifier was turned on I put my ear against the speaker to find out if there is any humm. During the first few minutes there was a little humm/hiss, but after about 3 minutes the speakers were dead silent. Also the power transformer isn't vibrating.
It's way too soon to make any comments on the sound quality of the device; i've been watching TV with the 2a3 amplifier, sounds good. Comparing to my Sweet Peach FU50 amp, the bass doesn't go as deep, but this is just an early observation. Once the tubes are burned in I can do a full review on the sound.
The tubes:
2x Shuguang 2a3b tubes
2x 6N8P pre tubes
1x 5Z3P rectifier tube.
Hello Mr Siqdiz. I have listend to a SV-2A3 at Hino company (ground floor of Sun audio)in Akihabara in Japan. the SV-2A3 letted me listen to brilliant piano sound thru an ALTEC(coaxitial 10inch undefenetly). I like direct heating triode amps(like 2a3 , 300b , 211).I have 300B SET(12AX7+6BQ5 drive) (?????????/JB 300B ver.3/???????? ??????) I can listen to the richest mid low(tone)sound thru this 300B(JB-300b) But I think that 300B can hardly win against 2A3 SET on Violin or flute sound(high tone).What do you think about that?
This Jewelry Box 300B is US $ 1,100.( tubeless model is about $780 ?????????/???????? ?????? ) This amp makes mid,low ranges richness sound.(with a lot of 2nd harmonic distortion) The high range(Violin Flute) is with poor 2nd harmonic distortion.(but clear) But right hand of the piano is very very beautiful (full harmonic distortion). I like 2A3SET better than 300BSET about violin, flute or harpsichord.
If you want to get good sounding amp, don't waste only with this. The quality of the components such as power/output transformers, resistors and capacitors are very important. To upgrade and modify the amp, it would cost about the same like builidng one.
Save the money and build a really nice one with good quality components.
JOhnny
Save the money and build a really nice one with good quality components.
JOhnny
This is the first DHT amp I've owned, I can only cross-reference against a Mengyue EL84 push-pull and a Sweet Peach FU50 SET. I've put around 10 hours on the 2a3 tubes now, when I've put around 100 hours in them it's time for a proper comparison against my other amps. Initial impressions are pretty good, although the FU50 SET wins in the bass department hands down. Again, only after a good amount of hours I'll compare the 2.
418 dollar excluding airmail, VAT and custom duties. Surface mail is free if you have the time to wait 2 months.
I listen all kinds of music, classic / electronic music / jazz / etc. I even watch movies with my amp. For me an amplifier needs to perform good in all those genres.
You've had this amplifier too?
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Hi
Congratulationson yr new "Sun Audio" amp.
I own the same since a year or two.
The power transformers are the "Bez" kind, like sold on DIY Audio... Check if yours is marked 220 v or 240. If it turns out to be 220, looks like you'll be running a hot amp! (or, at least power transformer!)
Second; get rid of the filter-caps in the power supply; mine was fitted with a 400v rated 40mf number, the second one turned out to be a 500v 80 mf!
I replaced these with a single can cap rated 500v 2x47mf (exactly like the Sun).
The difference was amazing!
Then get rid of the volume-pot and get hold of an Alps type (50klog blue).
Alltogether, I am very happy with this baby!
Congratulationson yr new "Sun Audio" amp.
I own the same since a year or two.
The power transformers are the "Bez" kind, like sold on DIY Audio... Check if yours is marked 220 v or 240. If it turns out to be 220, looks like you'll be running a hot amp! (or, at least power transformer!)
Second; get rid of the filter-caps in the power supply; mine was fitted with a 400v rated 40mf number, the second one turned out to be a 500v 80 mf!
I replaced these with a single can cap rated 500v 2x47mf (exactly like the Sun).
The difference was amazing!
Then get rid of the volume-pot and get hold of an Alps type (50klog blue).
Alltogether, I am very happy with this baby!
Hello,
After living with this amp, can you you give us an update on how you like it in your system? Also has anyyone else done any modifications on the Bowei 2A3 amp? I'm looking for ideas. Thanks.
David
Hi David, this "system" sits on the window bench of my home office, a 180 sqft room with a hardwood floor. I use this with a pair of british made bookshelve speakers, 2 way, that are over 40 years old with new filters and tweeters. I play it with a Marantz cd40 player, modified with a valve stage and the anti-plop cirquit removed. A Thorens turntable with a Ortofon om30 stylus and also a valve preamp. Tuner is a 7ties Sansui that I narrowed the tuning bandwith of, by changing the filters (ceramic capacitors) and a better power supply. All together this sounds like a million dollars to me withe the music I love, jazz and vocals and occasionally classic! Note, I don't push it to it's limits... I replaced the big bulb rectifier with a 5ar4 vintage rectifier; it is better and wont't grill the pant of the power transformer housing as well. I pulled the 6sn7 s and replaced them with -also- vintage RCA's -the same type of course-. You may consider changing the coupling capacitors (easy to locate - they connect the pre- and output boards-!) with paper in oil numbers (Russian are cheap!). Lastly and if you have some spare holidays left you could tear the innards out and start soldering the whole thing point to point; nothing would come closer to the Sun but it takes considerable time and experience! So, if you do the above plus the changes in my earlier post it gets as close -as it could- to a SV2a3 as it possibly could! Go and enjoy!
I also have bought a Bowei 2A3 amp.
At the start, I had many problems with this amp.
The hum pot problem made problems, the cathode resistor broken and one tube socket of 6SN7GT broken.
I have replaced the OPTs.
The originals ones are very poor.
I have used now James 6123 HS, they are much better.
I also use the ECC 40 as driver, instead of 6SN7GT.
The sound is very very good compare to the price ratio.
At the start, I had many problems with this amp.
The hum pot problem made problems, the cathode resistor broken and one tube socket of 6SN7GT broken.
I have replaced the OPTs.
The originals ones are very poor.
I have used now James 6123 HS, they are much better.
I also use the ECC 40 as driver, instead of 6SN7GT.
The sound is very very good compare to the price ratio.
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