I Didn't Do My Homework

Over the weekend I was fortunate enough to find a local pair of pristine Infinity IRS Beta speakers for sale. I had been looking for a local pair for five years.

I downloaded the owner's manual from a website and found out that due to their vintage, all connections to and from the servo controller to the amps are unbalanced. Of course I've just purchased two pair of Pass Labs X-600 monoblocs to drive them. These Pass amps only have balanced connections. I am going to have to get XLR adapters to make this setup work.

Am I going to suffer any degradation to the sound due to the adapters? These Pass amps were designed to be used with balanced connections. Will the design intent be compromised by using adapters? Also, I will need a run of about 20 feet. I have read somewhere on Audiogon that XLR's are better at longer runs than RCA's.

The guy that I purchased the speakers from was using a pair of Pass stereo amps, the X-250, that have both XLR and RCA connections.

I love these Pass amps. I hate to think their performance will be compromised by an RCA connection (adapter).

I understand that Cardas makes a good adapter, but imparts a sort of dark sound to the system.

Any comments or past experience on any of this will be appreciated.

I think BAT makes an adaptor also, you could try both for around $100. That said, I own and have used the Cardas adaptors at times in my systems...sounds fine to me.

Btw, Congrats on the IRS Beta.

You can get balancing transformers from Jensen. These are the same type used by Rowland Research, Audio Research and other high end companies.
there was a very recent thread on XLR-->RCA adapters & I believe that you contributed too (?). There were a number of members, who I consider have their heads on their shoulders, who said that the Neutrik adapters from Partexpress.com compared very, very favourably to the BAT & Cardas adapters.
Do find that thread & re-read it before you waste your money. FWIW. IMHO.
Yes, adaptors will imprint something on the overall sound, but it is a very slight something. I've used Cardas adaptors and generic $5 adaptors and could not tell the difference, both physically and sound wise. Hook everything up and enjoy. If after a few months of listening, things don't seem right, then obssess about the balanced vs. single-end connections. This hobby is supposed to be fun!
Space Tech Labs also makes a balanced transformer.
Why not talk to Pass Labs directly and see what they have to say? In my experience, they will go out of their way to help an owner of their gear, even if he's not the first owner. Phone number is 530 367 3690
Best of luck,

Look here.
Joeabrams, I took your advice and spoke to Nelson Pass. Sweetheart of a guy and gave me several solutions. The best one and most expensive one was to use Jensen Isomax Stereo "Pro" to "Consumer" Converter / Isolator at $210 per stereo pair. I will need two pair. There were couple other ways to go that were less expensive, but I'm in waay too deep now to possibly start to compromise everything I've done so far.

The model number is PC-2XR.

Please see the link below for the web page.


....thanks to all of you for your responses.

I would like to know what you think of the Betas.
The Betas are outstanding. Every superlative that you've heard about them is true. It took me a month to finally dial them in to my room. I have a huge room, and because they have room to stretch out....they really sing.

Find yourself a pair and buy them.