Are Usher amps just lookalike or buildt on licence?

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LTK

Member
Joined 2003
Could somebody please tell me the bias setting for the R-1.5? I've one of these amps which required the output stage repairing, the emitter resistors came off the solder joints and shorted out onto the heatsinks
Its had a full set of output transistors fitted
 
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amp_guy

Member
Joined 2004
wait a minute did I hear right , the new Usher products have motorola outputs? ummm that is interesting where are they finding that many NOS parts? Motorola semi's became Onsemi a long time ago. Anything new with a motorola logo is most assuredly a fake.
Or did I not understand what you were saying?
 
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ArneD

Member
Joined 2009
georgehifi said:


moe, yes the circuit is posted, back on post 6 of this thread, it has an extra gain stage which makes the amp a little more dynamic than the original S300 II Threshold. As if the the s300 had an Achilles heal it was a little slow/soft sounding.
This seems to have addressed the probelm all else is basically the same except for the bias, Usher ran it at half the bias of the original S300/S500 mkII's even Nelson commented that it would help if it were biased up harder into Class A as this circuit can benifit from that. Here is the circuit again of the R2.5 Usher

Cheers George
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Hello George,
I am new to this thread but have enjoyed reading it. You seem to be an advocate for the Usher Audio R-2.5. I am in desperate need for lots of power for my dynaudio Confidence 5 speakers, which are currently fed by a NAD M3 intergrated. Though the M3 sounds pretty good it doesn't seem to be able to push the bass driver of the C5 enough to produce an accurate sound image. While I was doing my research on potential used power amps to consider as a replacement for the M3 I found this thread talking about all the amplifiers I am interested in- Threshold, Nakamichi P7mk2 Stasis, Pass X250, Usher R-2.5. They all have one thing in common- Nelson Pass design, right?! I am under the impression that the Usher is a remarkable piece of amplification and am tempted to give it a try over the Nak Stasis or the Threshold. But how would you rate it against the Pass X250?
I would highly appreciate a word of wisdom! Thanks
 
georgehifi

georgehifi

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Joined 2003
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I wouldn't comment unless I lived with both, I would say though the X250 is not the same design I think (Nelson will probably help here) as the Usher 2.5 the Usher is a close copy of the older Threshold S300mkII. So you would think that the X250 having Nelsons later circuitry it will have the better sound.
Funny you should bring up the Usher thread again a friend said there's a 2.5 going either on ebay or audiogone yesterday for just $1000us.

Cheers George
 
Nelson Pass

Nelson Pass

The one and only
Joined 2001
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Actually if you compare the Usher schematic posted here against the
Threshold schematics, you will see that there are quite a few differences.

The Usher has a different front end - it is biased by different current sources
and uses current mirrors off the input stage and has a differential VAS. The
first does not regulate as well, and the last two create a higher open loop
gain (for more feedback). The bias system is different and is placed after
the drive stage, not before.

The output stage is pretty similar though.

You may prefer the Usher, but I would not call it a close copy.

:cool:
 
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ArneD

Member
Joined 2009
georgehifi said:
I wouldn't comment unless I lived with both, I would say though the X250 is not the same design I think (Nelson will probably help here) as the Usher 2.5 the Usher is a close copy of the older Threshold S300mkII. So you would think that the X250 having Nelsons later circuitry it will have the better sound.
Funny you should bring up the Usher thread again a friend said there's a 2.5 going either on ebay or audiogone yesterday for just $1000us.

Cheers George
Click to expand...


Thanks to both of you, George & Nelson, for your replies. You guys rock! Indeed there is an Usher 2.5 for sale right now on ebay- currently the bid is at $1650 USD. One more day to go. It will probably end above $2k I assume. Maybe I should shop around for a used X250 instead. I just replaced my power cord on the NAD M3 with a brand new PS-Audio AC-5, they just started to ship those. Couldn't believe my ears what a difference that new power cord makes. The Amp sound a lot more dynamic and pushes the bass on my C5 with a much stronger impulse, wow! I strongly recommend their new power cords.
Cheers,
ArneD
 
T

tomopazo

Member
Joined 2006
Blues said:
Usher, I think is based in Taiwan(?)...it looks like they're as shy as DIYZone.
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Yes, they are in Taipei, Taiwan. I was walking around Taipei 10 years ago on a business trip and walked by their store. When I went in and saw their amps, it was immediately obvious to me that these were Threshold clones, at least from the outside. They did have one open and I was impressed by their construction and craftsmanship.

Tom.
 
C

chicagorwc

Member
Joined 2011
Hi there i am new here and own since last year a Forté a1 with a Forté model 2, both bought from the first owners, both from Germany. I also have a DIY B1, bought from the own that build it, and I prefer the sound and the transparacy of the B1 but also like the balls of the model 2. A question, i would prefer a bit more bass from my SF Extrema's, the sound is very open and clear with very good artecultion also in the lower registers, but i would like a bit more push. Can somebody give me an advice, could extra coupling caps (quality caps ) on the power caps (the big electrolyt one's) bring more push?
Thx for a helping hand in these. Grtz Ruud
 
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