Luxman SQ38FD tube amp question.

[bjlefebvre]

Looking at a Luxman SQ38FD right now. But reading up on the AK forums, hearing about the difficulty of sourcing the 50ACA10 output tubes. Anyone have experience with this one and how easy/difficult it is to maintain? Not sure I want to drop ~$800 on an amp that needs ~$800 worth of replacement tubes down the line. Current owner says he never changed the tubes but that the amp "works fine." I keep going back to the first part of that sentence.

http://www.thevintageknob.org/luxman-SQ38FD.html

For my last major audio purchase in Japan, It's either this or a Luxman SQ505x of which the current owner cleaned up the guts, added new toggle switches and installed new RCAs. The only thing he did not do that I wish he did was replace the caps.

 

[Tinkerbelle]

That tube is where you have the catch. There were apparently Chinese versions made at more reasonable pricing but have no idea of quality or if still available. The 50CA10 is a 12-pin 50V filament 30W tube, so no direct equivalent AFAIK. You might try a search to see if anyone has documented a redesign around regular 12v or 6V power tubes - if they have it would not be a small project.

 

[bjlefebvre]

Yeah, a fellow AKer is testing the Chinese versions as we speak. He'll get back to me with the results later. One thing is there is such little out there in English on Luxmans as far as how they sound. People tend to focus on how they look. Only one way to find out....

 

[Dandy]

No experience here, but Luxman transformer quality is attractive.

I personally would much prefer the tube amp. With the Chinese tube option, at least you know you're not going to be left with a boat anchor. I see there are 6V versions of the tube, 6C-A10, but they are just as expensive NOS. You might ask someone to look at the schematic to see how hard the tubes are run. Will it continue to be run in Japan at 100V?

There is some info here about a tube workaround, and a readable schematic: http://www.wiredstate.com/forum/viewtopic.php?f=11&t=24657&start=200

 

[bjlefebvre]

Found a schematic at hifiengine (http://www.hifiengine.com/manual_library/luxman/sq-38fd.shtml) . I'd take it to the States with me and get a Japan-to-US voltage transformer. Still kinda considering it - read in another forum someone mentioning that those tubes tend to have a long life, at least in those amps. Right now I have a bid in for a SQ505x. If I don't land that I'll take another look at the tube amp. At least with the SQ505x I've found manuals in English as well as schematics.

 

[spaceysounds]

An old topic but I'm considering the SQ38fD as well, how did it turn out for you? Is it necessary to plug in the 50ACA10 tubes if you just want to use it as a preamp?

 

[bjlefebvre]

I gave it a pass - looked great, but I was a little apprehensive about the exotic tubes. I ended up getting the SQ505X, used that for a little while, but eventually sold it to plow the money into a Decware Mini Torii - which I really like. Sorry I couldn't be more help. But if you do get one, please tell us what you think. It would help to have more info out there on these Luxman's.

 

[smurfer77]

I believe I am the AKer being referred to with regard to testing the chinese 50CA10 tubes. I will let you know how it goes after I recap my SQ38FD and my MQ60s etc. Actually I have recapped the MQ60s so it's just the SQ38FD to do and then I will do a big luxman shootout (MQ60, MQ70, MQ80, SQ38FD).

 

[spaceysounds]

Looking forward to it!

 

[Mark 1234]

I believe I am the AKer being referred to with regard to testing the chinese 50CA10 tubes. I will let you know how it goes after I recap my SQ38FD and my MQ60s etc. Actually I have recapped the MQ60s so it's just the SQ38FD to do and then I will do a big luxman shootout (MQ60, MQ70, MQ80, SQ38FD).

How did the test go with the 50ca10's

 

[smurfer77]

How did the test go with the 50ca10's

Still haven't compared.... those original NEC tubes are so robust. Well I must get to testing soon though and doing a comparison.... thanks for the reminder