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Part Sourcing Assistance/Advice Thread


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The singles aren't hard to match (for Idss), and most of the time are closer matches than what is in the duals (at least from my experience). Linear Systems makes the LSJ74, which seem to only be available thru diyaudio.com in lots of 8 for ~$50. I think the 2SJ74s can still be had? There had also been a run of heat-sink thingies for grouping pairs of these into a single connected unit, but those are probably unobtanium anymore.

 

I would pull the 2sj109 and test it if I were you. Someone familiar with the SRM-3 may pop in and give you more enlightened advice.

 

Well they are desoldered atm, how do I test them? Diode test according to the datasheet as if single fets? I did it briefly while they were still in the amp and my dmm still gave me values, might change now that they've been isolated from the rest of the circuit?

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Lookup JFET Idss testing. Quite easy, all you need is a battery (like a 9Vdc) and a DMM to measure current (mA).

 

Like this (which came from the original Gilmore dynamic thread or the dynahi thread on head-fi)

 

http://www.diamondstar.de/transistor_matching_jfet.html

 

And yes nopants, those are the ones I was referring to. Didn't know you could still get those.

Edited by Pars
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It's time to replace the output tubes on my Anthem Integrated 1 amp.  I bought it used in 1997 and it came with Sovtek EL84 output tubes.  I need 2 matched quartets or, even better, a matched octet.  So this means current production tubes.  Could you please recommend current production EL84 (6BQ5) tubes and a seller who can provide the matching.

 

Thanks in advance for your advice.

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Marc, I checked out Upscale Audio's web site and found that all their EL84 tubes are much more pricey than I want to pay.

 

Antonio, thanks for the JJ recommendation.  I couldn't find any mention of matching on the Tube Depot site so I googled for a matched octet of JJ EL84 tubes and found this:

 

NIB Matched Octet JJ EL84 Amplifier Power Tubes

 

The seller has great feedback and the price is as good as anything I found, so I ordered an octet.  I'll let everybody know how much I like them.

Edited by guzziguy
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I guess that guy can match the tubes as anyone else if he has the tester. The Tube Depot has the matching service, you just need to check the box above the add to cart button, but you're right there's no third party reference about their matching quality. I've got tubes from them previously and work great, but I don't have the equipment to check them  :-

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I guess that guy can match the tubes as anyone else if he has the tester. The Tube Depot has the matching service, you just need to check the box above the add to cart button, but you're right there's no third party reference about their matching quality. I've got tubes from them previously and work great, but I don't have the equipment to check them  :-

 

I never saw the box for matching.  I use Firefox with the NoScript add-on.  I allowed tubestore.com but not everything needed to see the box.  After I allowed "everything on the page" then I could see it, but it was too late.  I hate it when pages use other websites to implement dynamic parts on their page.

 

You might check with Jim McShane... good guy and seems to know his shit

 

http://www.mcshanedesign.net/tubes.htm

 

He definitely seems to know his stuff and, from reading his site, likes the tubes I had already ordered.  His price is higher than I paid.

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With this lot one really must define not crazy or meaningful advice cannot be given.  It'd also help to know if you need 2ch or 4ch since you can use either with the designs you're mentioning.  Not everyone needs 4.

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It's time to replace the output tubes on my Anthem Integrated 1 amp.  I bought it used in 1997 and it came with Sovtek EL84 output tubes.  I need 2 matched quartets or, even better, a matched octet.  So this means current production tubes.  Could you please recommend current production EL84 (6BQ5) tubes and a seller who can provide the matching.

 

Thanks in advance for your advice.

 

I am late to the party, but I'll second Tube Depot, Jim McShane, and JJ EL84's.

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With this lot one really must define not crazy or meaningful advice cannot be given.  It'd also help to know if you need 2ch or 4ch since you can use either with the designs you're mentioning.  Not everyone needs 4.

 

I'd like to spend no more than say $200. 4 channel - so two balanced. 

 

 

spritzer's alpha pots are hard to beat

 

but there are many options if you want dual mono, like noble/tkd/alps black blah blah

 

or relay attenuator (amb, twisted pear, gilmore audio)

 

Where can I get the alpha pots? Or a link to any of the other options? I did some searching but that wan't too useful. 

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I'm not selling them any more as my stocks are dwindling.  I have the pcb's for the TKD/Alps RK27 too.  Also some used stereo DACT's that I need to get rid of at some point. 

Edited by spritzer
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I used an alpha pot and 2x tkd 601s. Have a khozmo 4ch as well that's not being used. Nate did you have to do anything special with yours as far as cleaning, dis/re-assembly, etc.? 

 

If you have a preamp you can also just use that in place of the pot, a la Kevin's original BH

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I used a 4ch Khozmo, but that's out of your budget and even if it wasn't I'm not sure I'd really recommend it.

 

Ah, Khozmo is one I've not come across. The stepped attenuators quad is $289, I could swing that. OTOH plus $50 for shipping (!), I might as well go Elma. 

 

By the way what is the recommended impedance for KGST and KGSSHV, 100k?

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