I haven't read thru this long thread so I apologize if this has already been posted:
Some ARC amps cannot take a single need output into their XLR input without major issues. Per ARC, They lack a phase splitter and require true balanced signal in. I know this was true of my VT 130 SE and I suspect that it's the case here.
I posted a thread on this issue some years back that got good responses from some of the techier types here and you should try to find it if only for educational value.
Im not sure, but I believe that the Bottom line is : Find a preamp with true balanced out via XLR if you ant to use you 150.
Contact ARC to be sure.
Good luck |
Al,
IIRC, that is exactly the result ARC described. In my post above I suggested that the OP try to find an earlier thread on the subject of ARC amps that behave this way. In that thread, there was a long, technical debate as to how power output could be quartered in this circumstance. I don't recall specifics, but after much debate, one 'Goner who is a service tech confirmed the phenomenon by putting a unit on a test bench.
The OP apparently tried to troubleshoot this problem by switching preamps, but my guess is that his alternative preamp didn't output true balanced, either.
I'm speculating, but having been down this road myself, my guess is that the OP needs a true balanced output to fix this problem. |
My bad, I should have seen that ZD had confused me for the OP. To the best of my knowledge Pakwong's ARC adventure is still unfolding and we'll all have to wait to see how it plays out. |
Pakwong,
I switched out a Joule Electra preamp for an ARC LS 25 line stage. The sound was a little less romantic or "tubey", but the distortion disappeared. I'm not suggesting that you go this route (like all gear, the ARC stuff isn't for everyone), but a true balanced signal is a MUST for your amp. |
It's funny, because this thread is starting to feel like it will spin off much like the old thread I referenced above. Several people posting that a power amp cannot be forced to produce less output because it receives a single ended signal rather than a balanced signal. I undrstand that this result is unusual, but.....
For the record, a single ended signal via XLR adapter will cause a particular set of ARC power amps tp distort horribly at relatively low output levels. Per ARC. Per my own experience. Period.
Whether he replaces his preamp or inserts a transformer (as Al recommends) the OP needs to feed a balanced signal to his ARC amp. It's a design quirk, but once my VT 130 SE was appropriately fed, performance went from IMHO unusable (much as the OP describes) to outstanding.
My advice to the OP, don't screw around with any other fixes. ARC told you what to do about this problem. Either do it, or ditch the amp. Trust me, I've been in this precise situation and the solution is a balanced signal. |
To rephrase my post:
The OP may or may not have several issues with his system. However, if he's trying to feed a single ended signal into an ARC amp designed for balanced inputs he WILL have an issue very much like the one he describes. Per ARC, he should not drive his amp with anything but a balanced signal.
As a less technical type, I can only gather that the ARC design is unusual. However, I can assure everyone that the relevant ARC amps do, in fact, behave in precisely this fashion. |
Zd,
Some confusion here, no Wadia components in my house. I never sold the ARC amp either. In fact, I still use the ARC LS 25/VT 130 SE with Verity Parsifal Encore speakers and a Qsonix front end (which, come to think of it, does utilize a Wadia digital section).
I also kept the Joule preamp paired with Cary 300b mono sig amps and Merlin VSM SE speakers. Analog only from an Oracle/Graham/Graham front end. I still really like all of this gear and have been using every piece mentioned here IIRC for over a decade.
Most of my listening time is now spent in front of an Ohm (sometimes Magnepan) and Rythmik based system with an Onkyo pre-pro and rotating power amplification. Digital sources continue to vary but the analog front end is Acoustic Solid/Rega/Lyra.
Variety being the spice of life and all.... |
It's pretty rare when a real problem like that faced by the OP is posted and a straight up creative solution is offered by an Audiogon respondent. Congrats, ZD, you found a high quality, zero cost solution to a thorny problem. |
Pakwong,
You're a hobbyist and - if you're willing and able to bite the bullet financially - you might want to consider building two systems. I was in your position and kept both my Juole preamp and my ARC power amp even tho they weren't well suited for use together. I added the ARC line stage and Cary power amps to form two very different systems.
You ask which alternative A'gon posters here might recommend and I'd say that it's really such a matter of personal taste that recommendations wouldn't be very useful, so.... you could build two systems to compare them. If you see the value in each and can afford it, enjoy both. If you prefer one over the other, sell the electronics that come up short.
If you don't want to (or can't) pay for this option, you might try to borrow suitable partnering electronics for each component from a local B&M dealer (if one is available to you) for audition and keep the system that you prefer.
Owning two electronics chains may be expensive, and it may not be a rational decision, but who ever said audiophiles are rational? |
