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Posted
They need to get their JT attenuators in stock :sadcat:

I've spoke with Brian about this, the problem is multi-faceted. One the one hand they're co-developing the simple version of the JT with the full on uber controller version. The current line of thinking is that they'll release the simple version first, but there's no firm ETA on that. On the other hand the demand for Buffalos is huge and as a product that requires a lot of pre-assembly by Brian (baking and testing every DAC) it's easy to understand how that's bogging them down.

What they need to do is both outsource the Buffalo board production and raise the price a bit to compensate for that. That way Brian doesn't have to spend every hour of his day building DACs and can do some work on the JT replacement.

I wanted to use a JT a while back for a project and when I saw that the replacement was a good 2 months already overdue with no news I moved on. If you're waiting hoping to put one in your beta22 you might just want to consider an alternate attenuator. If you want I can try calling in a favor and seeing what comes of it.

Posted

Perhaps the person who assembled the one I am enjoying now may be available. Keep watching this forum for more details I would guess.

Posted
If you're waiting hoping to put one in your beta22 you might just want to consider an alternate attenuator.

I'd also recommend doing a bit of math and considering if it will work given the input and output impedance requirements. amb commented about this over at HF in a thread somewhere.

Posted
I'd also recommend doing a bit of math and considering if it will work given the input and output impedance requirements. amb commented about this over at HF in a thread somewhere.

Indeed. The JT only presents about a 2k load (and a variable one at that) to the source so tube output stages might present problems but most SS gear should work just fine.

Posted
Indeed. The JT only presents about a 2k load (and a variable one at that) to the source so tube output stages might present problems but most SS gear should work just fine.

I' dunno, haven't surveyed solid state sources. Amb seems to think that "many" will not work fine. Here's amb's reply:

"OK. 2.2K is quite low, users of the Joshua Tree should be mindful of source compatibility. A usual rule-of-thumb is that the input impedance of the amp (which is usually dominated by the volume pot/attenuator) should be at least 10x higher than the output impedance of the source. This means that the source should have an output Z of around 200 ohms or less. Many sources do not meet this criterion."

Posted
I' dunno, haven't surveyed solid state sources. Amb seems to think that "many" will not work fine. Here's amb's reply:

"OK. 2.2K is quite low, users of the Joshua Tree should be mindful of source compatibility. A usual rule-of-thumb is that the input impedance of the amp (which is usually dominated by the volume pot/attenuator) should be at least 10x higher than the output impedance of the source. This means that the source should have an output Z of around 200 ohms or less. Many sources do not meet this criterion."

Yes, I remember the discussion well and had it privately with amb long before that thread when I was thinking of using the JT in my first beta22 (I actually purchased and then sold a JT kit, just ask thrice ;)). As to how much you can violate the 10x rule and how many SS sources have higher than a 200ohm output impedance I can't say. I do trust amb's opinion on the matter, that's for sure, you don't see a JT in any of my gear do you?

Posted
Yes, I remember the discussion well and had it privately with amb long before that thread when I was thinking of using the JT in my first beta22 (I actually purchased and then sold a JT kit, just ask thrice ;)). As to how much you can violate the 10x rule and how many SS sources have higher than a 200ohm output impedance I can't say. I do trust amb's opinion on the matter, that's for sure, you don't see a JT in any of my gear do you?

nope. I have 2 though. I also have 8 JISBOS buffers :)

Just curious, do you know if any of the other TPA modules will be available tomorrow?

Posted

Just curious, do you know if any of the other TPA modules will be available tomorrow?

Not that I'm aware of. The only other project that I know of that's ready for production is the Sympatico amplifier but since they haven't even sold the few that they had ready at the introductory price I doubt they've pushed ahead with that.
Posted

I had waited for six months on the JT, boilermakerfan convinced me to go instead with two matched Optivol for $56 and used the money saved to help buy a buffalo since I had all the parts except for the buffalo and IVY kits.

I would do a shootout with the dual mono OPUS, but I don't think its relevant since I only have the WM8740 Opus that I bought less then two weeks before the 8741 boards were released. If anyone has any decent ideas on how to update them at a decent price to the 8741 without some hardcore SMD soldering, I would happily listen.

Posted
If anyone has any decent ideas on how to update them at a decent price to the 8741 without some hardcore SMD soldering, I would happily listen.

I'd jusk ask Brian from Twisted Pear if he'd do the swap for you if you sent him the modules.

  • 2 months later...
Posted

Expecting to hear more news about the upcoming new ESS Sabre32 DAC boards from TPA and counterpoint discrete output stage soon, looking forward to more impressions and hoping that it won't be another case like the OPUS so soon.

Posted

Yeah Filburt tells me that 32 bit doesn't really mean anything at the moment cept for things with 32 bit word length, but the SNR performance is at 135 which is a performance increase from the 24 bit version which was at like 12X or something. Plus it consumes less power.

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