Blue Circle Gear?

good stuff, many, if not most pieces performed above its weight class, so to speak

gilbert yeung, depending on who you talk to, is somewhere between a talented designer with a good ear to a downright genius (but evidently an incompetent business person)

gilbert is still around, but the company (and warranty support) is kaput...

With no warranty support I'd not be buying YMMV

Contact Walt Stagner, TLP Audio for all things Blue Circle.

https://www.tlp-audio.com/gilbertyeungdesigns.php

There is an authorised service shop for Blue Circle.

I would steer clear.....   

I've heard great things about this equipment.  You only live once...

"There is an authorized service shop for Blue Circle."

That would be-

https://www.dtsaudioelectronics.com/Authorized-Service.html

I don’t have experience with their preamps but did own a BC-204 amp that had issues. I would cringe every time I turned the amp on because I sometimes I would hear a loud pop noise. 

Certain defunct brands are worth buying ,  but I just wouldn’t with Blue Circle. 
 

Sonic Frontiers, different story as Parts Connexlon still repairs and mods them.  
 

Wow , that place has exclusive repair for many good brands...good to know .  Most of those brands listed are still in business.  

BC made some great sounding gear. No doubt about it. Good value used if you pay 25-30% of retail at most. Why? He built the amps with copious amounts of white epoxy holding the electrolytic caps in place. This goop covers all the caps and connections to the caps.

These caps do age and will need replacing now. What a major hassle to try and work on these now! This is enough to keep me away from the power amps.

The preamp in question is much easier to work on. He still used a clear epoxy to hold the caps and parts in place, but the goop is not everywhere like in his amps.

Any good tech can work on the preamp as the circuit is straightforward. Replacing the old electrolytic caps is still going to be a bit of a hassle with the epoxy build design. It can be done, but a hassle. These caps will need replacing as they are now some 19 years old! Figure this into the cost.

I was also interested in BC products but every time I saw them used, they were WAY overpriced ... products by manufacturer that no longer exist must be purchased at a good discount because they will have to be checked by a tech and it could be complicated to have them repaired if they break down ...

i still use gilbert's tlp power conditioners in the clear goo inside the pvc pipes... those seem to work well

Had a BC DAC for a number of years , good sounding and trouble free. I still have in my main system a BC6000 power conditioner that also has been trouble free and positive SQ benefits