Sun Audio SV-2a3 HK Clone

[siqdiz]

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.

[siqdiz]

reserved for photos.

[harakiri]

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?

[bigjppop]

That's a great looking amplifier. How much did you pay, if you don't mind my asking? I'll be looking forward to you impressions.

[harakiri]

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.

[kmtang]

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

[siqdiz]

Originally Posted by harakiri

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 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.

Originally Posted by bigjppop

That's a great looking amplifier. How much did you pay, if you don't mind my asking? I'll be looking forward to you impressions.

418 dollar excluding airmail, VAT and custom duties. Surface mail is free if you have the time to wait 2 months.

Originally Posted by harakiri

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.

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.

Originally Posted by kmtang

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

You've had this amplifier too?

[ksporry]

Just a suggestion, if you have multi way speakers, why not biamp? Use low tone suitable amps for low drivers (eg 300b set for bass/low) and maybe 2a3set for mid/high tones? Doesn't work with full range drivers ofcourse...

[siqdiz]

I'm running full range horn speakers ( Das Viech with SICA 426 drivers ), they have no usable output below 50/55 hz. Soon I will be looking into designing stereo subwoofers for 30-60 hz, this will fill the bottom gap.

[henk1961]

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!