SX-Amp and NX-Amp

[fab]

Hi Guys,

I bought the Jim's Audio boards. Is there a BOM posted somewhere? I asked Jim's and he gave me the link to Andrew's site. I downloaded the PDF but can't find the BOM. If anyone has one I would appreciate it. Did a search and still can't find it.

Thanks, Terry

http://hifisonix.com/wordpress/wp-content/uploads/2013/11/The-Ovation-nx-Amplifier-V2.0_61.pdf

See pages 46 and 47.

Thanks

Fab

 

[still4given]

Thanks Fab,

I must have scrolled too quickly.

 

[meanman1964]

Recieved my NX boards from Jim's Audio.Exellent quality

 

[Junie]

Welcome to NX club.

 

[meanman1964]

Thanks,now it's time to collect the parts.
Junie,did you use a 2 x 35 Vac toroid?

 

[Bonsai]

Yes welcome.

 

[meanman1964]

Bonsai,can I use 35Vac?

 

[Junie]

Hi Patrick, yes I did use 35Vac.

http://export.farnell.com/multicomp/mcta500-35/transformer-500va-2-x-35v/dp/9532951?Ntt=9532951

 

[still4given]

I ordered a 400VA from antek on ebay
400VA Antek Power Transformers An 4234 | eBay
Item #370951442131

 

[meanman1964]

I've this one from Schuro

 

[still4given]

What are you guys using for the TIS transistors? I can't find them in the same grade.

Thanks, Terry

 

[still4given]

The Antek transformer arrived today. Unload it puts out 36.7VAC and rectified is right at +-50VDC.

 

[Ian Finch]

Bought a set of boards from Jim's Audio

Hmm...I've been trying to order from Jim's Audio Store but his site message advises he won't sell to me. I assumed they were taking a seasonal break, but a bit early yet for Chinese New Year .

I have never had an unresolved problem there or with other Hong Kong stores but has anyone else had a recent problem too?

 

[still4given]

I bought mine on Jan 5 from their ebay store. They hit San Francisco today so I should see them first of the week. Are you trying to buy them through ebay?

 

[Ian Finch]

Yes, through Ebay. Thanks for the reply and good luck with the project. It seems I'll have to contact them and find out the problem.

Re: The Hfe range of TIS and drivers.
Fairchild and Sanyo (the OEM of 2SC3503/A1381) Hfe grades are C,D,E,F. I think current Fairchild stock is grade D only (that's Hfe 80-120). Bonsai specifies O, Y grades in the construction article, which probably refer to another part because they sound like Toshiba ranges. It's possible he didn't notice this when revising the schematic and BOM for the Fairchild parts or perhaps some other reason.

 

[still4given]

Yeah but the C3503 are D grade and the A1381 is an E grade. I can't find them in the same grade.

 

[thimios]

c3503

Yeah but the C3503 are D grade and the A1381 is an E grade. I can't find them in the same grade.

Hi Terry .
Have you used these,c3503d and a1381e, in VSSA amplifier?
Best regards.
Thimios.

 

[BobEllis]

You might try buying a quantity of each and hoping to find that there are enough close to the limits of their grade to make a decent match.

Also, I wonder if it really matters that their hfe-s match. Bonsai?

 

[jkuetemann]

You might try buying a quantity of each and hoping to find that there are enough close to the limits of their grade to make a decent match.

Also, I wonder if it really matters that their hfe-s match. Bonsai?

Tried that. I have 100 KSC3503D and 100 KSA1381E purchased in bulk packaging that are useless for getting matched pairs, the manufacturing consistency is too good. There were no high and low outliers, all very similar. Some members have scored small quantities if old stock KSA3503E to mate with new production KSA1381E that seem to work well.

For my other builds I went with a different device that seems to work well but doesn't have the same specs-appeal as the KSC3503 / KSA1381 pair.

 

[still4given]

Hi Thimios,

Yes but PMI sent both of them in E grade. Can't find the E grade in 3503 now. I guess he had a stock of them.
Hi Bob,

I should check my parts drawers and see if I have any.