Search results

His name is Tom Ishimoto of Northridge electronics. He doesn’t seem to be taking on repair work much anymore and closed his shop, fyi. I’ve been politely pestering him for most of this year to finally get the SCU to him a few days ago. He’s a brilliant guy though, former marantz engineer, and...

The upper amp has an output gain of 22db. The woofer amp is 32db. Using RCAs, but I have been looking for replacement amps with balance connections. I did a quick measurement of the volume difference, after connecting the servo cables, woofer volume output drops about 20db. I also just heard...

I wish it was that small of a change. My woofer amp has an output gain that is 12db higher than the mids/tweeter amp. So SCU as a crossover, I set the rear bass gain dial to -12db and the outputs seem to match well. With the servo cables connected, I can set the rear dial up to about +2db before...

How would I take measurements of the accelerometer on my IRS Epsilons for troubleshooting purposes? I have an appointment next week to bring in my SCU to an Infinity expert. While explaining my issue over the phone (major gain drop in woofers when servo cables are connected), he suggested I...

Thats totally reasonable!

Read my above comment, that's helpful info though! I dont think you're in the Los Angeles area, but if I dont find someone local, I'd love to ship it to someone to test in their system, if that's something you'd be open to.

Damn! I thought I was on to something! And I just found the other thread where you and okeeteekid already went through the same ID shenanigans. Are you by chance in/around los angeles? I'm hoping to find someone local that would be willing to test out my SCU & cables in their system so I can...

Well I’ve been trying to figure this out since January and I think you just solved the puzzle for me. I opened mine up today and my PCB’s are Rev B. Both my speakers and SCU are labeled as Rev A’s. So if I’m understanding correctly, I also need to upgrade my PCB’s to Rev C? I’ve never had the...

I understand now. Infinity made this a bit confusing by having the Rev C PCB in the Rev A speaker. I'm surprised it has worked with no issues as they claim it could cause damage to the system. Did you mockup the color diagrams on the PCB layouts yourself? I thought I had every Epsilon...

Would love to see this. Could you explain more on what this change will do? I have only seen this in the service manual that mentions "performance improvement"

As far as I know they’re based in Atlanta.

What would some of those variables be?

I'm hoping someone can shed some light on this issue. I recently "upgraded" from a vintage C30 preamp to a modern C8 tube preamp. I believe the C30 is all original. I expected the new C8 (purchased used, low hours), to add a bit of that tube "warmth" to the overall sound, but it seems to have...

Just following up that I still have not gotten the servo functioning properly. I built the servo cables, but when connected I'm getting a ground loop hum in the woofers and they are definitely under performing. The problem is either the way I built the cables (very possible) or maybe there is...

They did, specifically with Krell amps of the era, something to do with biasing instantly maxing out and the everything going haywire. Fortunately they fixed this in their RevA which I have. But definitely I’m on the hunt for an amp upgrade with gain controls and balanced connections.

I had planned on upgrading anyway as I’d like to have everything running with balanced connections, but that’s a good tip on gain controls. The big meters are kind of cool on the onkyo but it’s honestly so bright that I can’t even see the needles moving. I didn’t know about their lacking range...

I really appreciate the help. My presumption would be that the Onkyo (bottom amp) would have a db gain output of something around a typical 27db and it's being used to power the woofers. The Van Alstine (top amp) I have powering the mids/highs has a stated output gain of 20db. The servo...

A Van Alstine Ultra Fet Valve 500. This will be the 5th set of Infinity speakers I've owned and the second set of their IRS speakers. My comment above has a link to the service manual if you're interested in those schematics.

https://drive.google.com/file/d/1PBU8fUhzean4sfkAxFXN7VGgxrkgrrlc/view?usp=share_link

so just to clarify, are you unable to answer my posted question? The actual gain calculation is important here, for a number of reasons. While I appreciate your suggestion, it doesn’t accomplish what I need.

Do you mean a bare speaker? If so, I don’t have that available. How do I get the output gain from that measurement?

preamp into a servo controller, then servo controller to both amps. Cannot adjust gain of both amps independently. Which is why I asked the question of how to measure the output gain of an amp so I can ensure I’m utilizing two amps that match output gain within 6db.

Neither amp has gain controls though.

Do you mean the frequency of the input signal? I did the measurements with a 50hz test tone, if that’s what you mean, when I tried testing with music playing it fluctuate too much. That’s good to know about the accuracy! To measure the voltage in, would that be as simple as running the same...

I need to match two amps within 6db of each other for use in an Infinity Epsilon system. The output gain of one amp is 20db. The other amp is an Onkyo m504 and I can’t find the specs for that anywhere. With a multimeter and a full signal going to the amp, I measured 4.5v (ac) at the speaker...