Hello All,
I have recently purchased Usher 1.5. I like the quality of this Amplifier, especially in the vocal and bass area.
I felt Highs are bit rolled off and need an improvement.
I have figured out Power capacitor change in Usher 1.5. Which will be the best-suited capacitor? Changing these capacitors will improve sound quality?
It is believed that Bias setting in Usher 1.5 needs to increase for better performance. If true, please let me know how to change the Bias setting.
Please also enlighten me about other modification can be carried out in Usher 1.5.
Many thanks in advance. |
Hey Guys,
Just wanted to share that I have the Usher 1.5 amplifier in my reference system right now. The amplifier was re-biased by the individual I purchased it from to a higher class A bias. This amplifier is wonderful! It easily is on the same level as highly regarded Pass Labs pieces and drops tons of current to really control bottom end frequencies. It's overall a touch warm/full with a sweet top end and great overall dynamics. The build quality regrading internal parts and chassis are excellent. This amplifier is a real "sleeper" when it comes to cost vs performance ratio. |
Stani19 came through! Thank you everyone, georgehifi, vvvinashhh, and stani19. Just sent to a couple of folks that were also requesting. You are welcome to PM me if you need the schematic in the future.
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I have not received schematic. I have sent PM to the parties requesting. Hope all is well with vvvinashhh. georgehifi posted a fairly small resolution schematic here: http://www.diyaudio.com/forums/pass-labs/55067-usher-amps-lookalike-buildt-licence.html#post616009 less then desired; however, provides enough information to figure things out. I have an Usher R 1.5 incoming replacing a Classe Audio DR-10 which are driving VMPS RM-30 speakers. With my gear I like to have a schematic if anything goes wrong. PS: Good input from
vvvinashhh
on factory bias of the R1.5 is 500mA.
In that same post I provided above there is a good discussion on process to increase bias. |
has anyone received a copy of the circuit diagrams yet ? |
Please send me the schematic
for the 1.5
deweyc@cableone.net I would certainly appreciate it!!! Thanks
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please send me a copy for r 1.5
mboldda1 at sbcglobal dot net
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I have the schematics .... please provide your email id. |
Man....is amps keep breaking down or what?
George said vvvinashhn has it.
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Hello George.
Is it possible to obtain a schematic for an usher 1.5 ?
Thanks in advance for your reply
regards
Dave |
kharp11 posts02-04-2018 9:34pmI realize this thread has a little bit of age, but, was wondering if anyone here still has a set of prints on the Usher 1.5 or 2.5 they'd be willing to send?
PM
vvvinashhh he has them.
Cheers George |
I realize this thread has a little bit of age, but, was wondering if anyone here still has a set of prints on the Usher 1.5 or 2.5 they'd be willing to send? |
hello everyone and forgive my english!
I would also like the electric diagram of usher r 1.5
I am in rome and my mail is: fiorillo.stani@gmail.com
thank you
Stani |
Your Usher has a fet inputs at 61kohm loading with a fair amount of gain. I would suggest a low gain preamp like a Schiit Freya for $699, bonus is you can use it as straight passive, a tube, or a solid state (to suit your moods? maybe) and it has a trial period. http://schiit.com/products/freya Cheers George |
Just bought a pre owned R1.5 and listening to it for the first time. My speakers are USHER 8571 II and thy were a bitch to drive. So far so much better with the new amp. I am using my old Rogue Audio Pharaoh as my pre at the moment but thinking of a tube pre... any suggestions out there???
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Thoughts on pairing this amp with a Modwright pre-amp ? I'm thinking of going that route as i currently have a Modwright pre.
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This amp is fabulous once mated to a proper Tube Pre Amplifier. Will uproot a $6000 McIntosh in Dynamics and Heft. |
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My mail id is right there and I have the schematics as George mentioned. What pre are you using desalvo55? I'm using a Cary Audio SLP03 and the results are pretty darn good. I have got to know that the factory Bias of the R1.5 is 500mA. So keep that as a reference point. These amps are simply fantastic and can be easily repaired by anyone who is experienced enough. Usher is going through a restructuring hence the delay. |
desalvo55
Thanks George, I’ve got an electronic savvy buddy of mine who designs amps. He’ll do it for me. Wish I had a roadmap to give him still. I gave the circuit diagram to vvvinashhh above, on the condition he passes it on, email him and he’ll forward it to you. Or send me your email,, and I'll send it, with the bias pot circled in red and the emitter resistors in red, which need to be monitored with a dmm when adjusting the bias pot Cheers George |
Thanks George, I've got an electronic savvy buddy of mine who designs amps. He'll do it for me. Wish I had a roadmap to give him still. |
But I don’t know how to set bias :( So I guess I’ll "probe" around, find a pot, and adjust till my hand starts burning? Say goodby to your amp! Seriously, please get a tech to do it, as you need to put dmm meter probes on the emitter resistors, and that is a hairy place to be, as it’s very confined. Cheers George |
So glad I found this thread. I have 2 Usher 1.5's and run (ran) them in mono to a pair of Usher Tower XL's.
One of my amps became noisy (right channel) and was shipped back to USHER for a replacement. Still waiting....
What I had learned was that Usher was setting the bias higher as it was discussed somewhere that the sounded even better at higher bias, and they already sound amazing. What a great amp and a beast. In mono it's stupid good.
But I don't know how to set bias :( So I guess I'll "probe" around, find a pot, and adjust till my hand starts burning?
Thanks! |
Thanks George got you mail. Thanks very much indeed. Heard the amp extensively today and I can vouch that this amp will blow amps costing $6000 straight outta water. People looking for power amps should really check this Amp first before blowing money on Big Brands which are unnecessarily expensive for other reasons than the main reason ... The Sound.
I’m getting the R1.5 with a ss preamp later but a good preowned Shindo Auriges now . |
Sorry I have no idea about the V1 and V2.
I send the circuit diagram to you, Usher 2.5, same for 1.5 just less rail volts and output transistors.
Should anyone else want it on Audiogon can you contact vvvinashhh@yahoo.co.in and he will pass it on.
Cheers George |
Thanks so much George ! My email id is vvvinashhh@yahoo.co.in .
One more thing is there a Usher Version 1 and Version 2 ? I gathered this while talking to US based Usher dealer. Will that make a difference? If there's a difference then what is it and how do I differentiate cosmetically or internally between the v1 and v2? |
I had the circuit, but it’s long gone now, but if you warm it up with the lid on for at least an hour, and if still not warm enough (use Pass palm test) Monitor the bias across the emitter resistors (yes they used them the same way as NP did, collectors drove the speakers) with a DMM and increase 10mV at a time till you get the right heatsink temp, both channels.
And yes more cap uF the better on the power supply, but many small ones are better than big ones, as they can release their storage quicker and give you far better transient response.
PS: Just found the circuit of the Usher 2.5 send a PM if you want it with your email address.
Cheers George |
Can you provide the correct Bias settings for the Usher R1.5 and the schematics? How wise will it be to increase the filtering capacitors from 10k microfarads Nichicons to 20k same specs ? Will there be any benefit at all? |
vvvinashhh
I might also add the ones I've played around with, were under biased,, and needed to to be adjusted a bit higher to get the Class A bias of the Thresholds, "as Nelson palm detector adjustment", enough bias to keep the palms of you hand on a fully warmed up heatsink for at least 6 seconds, (bricklayer exempt from this test) Cheers George |
Thanks George, that was a great piece of information . It just reinstated my faith in the R1.5 and this forum. Im definitely buying it now.
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vvvinashhh
Usher R1.5 and R2.5 were almost direct copies of the Threshold Stasis S200 and S300. I showed Nelson Pass the circuits of the Ushers, and the only difference was they had one extra gain stage transistor in them, which Nelson replied was what he would have done if he did a re-design of them. So your in good company as I owned an S300 mkII and it was a very nice smooth amp with plenty of grunt. Cheers George |
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Pretty cold in here.... nothing? Where's everyone eh.... |
