nick72 wrote:
Hey Ian.
Double check the power supply on these monoblocks, they are way underatted also there is no soft start circuitry which will take its toll on the tubes.
We brought in a few of these monoblock when we where trying to market them 5 years ago.
I can see the innards are the same as back in the days, we had gotten a digital display installed in the front of the units to make user biasing easier.
The negative feedback for both the 300D driver and 845B tubes are kind of a pain in the %?*.
These unit once broken in sound very nice, bass i nice an palpable, with an open and transparent midrange that you would expect an 845 monoblock to achieve.
The caps in the power supply are underated like i mentioned , the caps are 450V kinds in this system you would need 600V caps to be safe, i had these checked out by a tube tech in T.O and said that it would be too hard to clamp down the design.
In china 600V caps are hard to source and that is why they where using 450V which is the highest value they can get off the shelf in big numbers.
I kept using these because they sounded good, after 6 months i noticed that the caps where starting to bulge in the center( about to burst) because they where underated for the application.
Below is a show report from rick Becker of enjoy the music showing the shuguang 845B amp at FSI 2006 we had on display.
http://www.enjoythemusic.com/montreal2006/becker/page4.htmThese are nice sounding amps but make sure that you look at any design issues before marketing if you are planning to do so Ian.
Thanks for the info, you had the 2nd generation that had the power supply designed by an English firm. Shuguang is on the the 5th generation now, dropping just about everything from the 2nd and 3rd generations (as I was told, never seen them) and we have tested 2 other amps in the series for NA at 115v +/- 10% and all is fine. The 845 is going thru 2 sets of safety tests with our techs. 450v caps is common for these amps, running them at 100v with a variac is going to cause damage as it was outside of the Brit's design, even for a few minutes. But I will have double check on the 845. I have the pre-amp pics on another camera.
Soft start ups are fine until they fail which is a problem with HV soft starts, these have a 30 second pre-heat since the last generation, seems fine. The tubes can take a normal start, what the tubes can't take is shipping. We have dropped all the Chinese big bottle tubes for now, they have made them sound great but they can't survive our crap NA shipping methods, in China you get them hand delivered.
Shuguang is one of the largest tube amp part manufactures in the world, it is easy for them to get whatever capacitor they want, to say otherwise is just your opinion and not much of one in my opinion ! The Shuguang amps aren't getting my name put on them, they offered. I like the ones that already have my name on them. Shuguang has been making tube amps since 1981.
Jolida does not represent what Shuguang can do, enough said.
Like you, I heard the 845s and went holy sh.., and posted, Rachel has already told me that I can only sell them local or without tubes. I just wanted to share what I was hearing and hopefully others will have a look at 845 amps as an option for bigger power SET. I also have the Opera Consonance Cyber 211 (which can also run 845 tubes with a simple bias change). I don't sell these at the moment either, they are twice the price of the Shuguangs, just amazed at what I heard off the top and after a few hours and the Treasure tubes need 150 to 300 hours to burn in.
Again thanks for the info. Look forward to seeing you in Montreal.
Cheers,
Ian