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Old 3rd April 2007, 08:07 PM   #1
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Default Comments on passive pre and cables

Hey folks,

Just wanted to let you know about an interesting experience I recently had. I know many of you have read my site, and know my thoughts on resistors, wire and solder affecting the sound. Well, until recently, I was of the opinion that they had very little if any affect on the sound of an amp.

Man was I wrong!

I auditioned a setup with a pair of high quality interconnect cables and a passive preamp/stepped attenuator that blew me away. You know how I believed that with my amps one finds oneself saying "I never heard that before"? I thought that there was nothing else that could provoke me into saying that myself. Until I tried this guy's passive pre and cables.
The cables are awesome. Right off by changing back and forth there was an audbible difference. Not subtle, not slight, but dramatic. He convinvced me that thinner is better! His wire core is something like 24 gauge. I use 20...

The passive-pre behaves as if there is nothing there. It is even better than my Alps Black beauty (I paid $35 for it!!! This from someone who uses Radio Shack $2 pots normally).
I am telling you, I heard stuff in my most intimate music I never heard before... Even bass was tighter and deeper... something I thought would be stifled by thinner wire. Everything else was airy and where it belonged.

Ok folks, I apologize if this isn't exactly allowed, but I just had to mention this because it has changed my thinking about wire type, thickness, and passive pre performance. And as an engineer with 30 years of prejudice in certain things electrical, that is saying much!

Here is the web site if you want to check his stuff out:

http://www.auralthrillsaudio.com

And the owner is a wonderful person to deal with, he's responsive, quick and dedicated to his product.

I believe they will make the perfect match with our great tunes amps.

Gabe
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Old 3rd April 2007, 10:29 PM   #2
phn is offline phn  Sweden
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I will more or less repeat two earlier, but unrelated, posts I've done here.

I don't know what "Alps Black beauty" is. But the more popular, and cheaper, Blue Velvet (I think that's the name) is pretty bad. It uses conductive plastic. I use Alps carbon pots. In my earlier post I called old carbon pots one of the "secrets" in audio. Better than just about anything else.

If the "passive preamp" (stupid name) had been mounted on the amplifier we would have called it an integrated amplifier. Unless you use a turntable there's no need for a preamp. It only serves a purpose for manufacturers who can charge twice.
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Old 3rd April 2007, 11:14 PM   #3
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Gabe,

I suspect that the cables you used are low capacitance. That's exactly what's needed at the O/P of a passive control center. I agree with phn; passive preamp is an oxymoron.

PECO makes SUPERIOR hot molded Carbon controls that will not put you in the poor house. DigiKey is the US PECO distributor.
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Old 4th April 2007, 12:07 AM   #4
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Folks.. I am only calling it a "passive preamp" because that is what many know it as. To me it is nothing more than a stepped attenuator.

May of you know me better than that... I hope.

I am only sharing my experience with the cables and the device.

The Black Beauty Alps pot I bought from Angela Electronics and was on sale and no longer made. I got it some three years ago.

The experience was real, what I heard amazing. And I do use low capacitance cable myself.

Anyway, I just thought I'd share...

Gabe
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Old 4th April 2007, 02:25 AM   #5
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I had very similar effect couple of days ago when increased gain of power amp and decreased gain of a Behr*nger EQ. The nasty thing stopped saturating. However, I've discovered that instantly, as soon as looked at line level meters.
The concert went smoothly as the result. I believe, a passive preamp between a pult and an EQ could help also, but fortunately the EQ has own line level controls.
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Old 4th April 2007, 12:43 PM   #6
Sherman is offline Sherman  United States
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I've not had this experience with hifi but a couple years ago my son needed a new guitar cable so we headed out to pick one up. The sales guy was recommending a cable from Planet Waves which was about four times the cost of the generic cables I'd always bought.

He pointed out the features of the cable some of which (like the spring/locking 1/4" plug) would have made it worth more than a regular cable but I was doubtful about any sonic difference. Bottom line- we bought one, took it home, plugged it in and wow! Less hiss than any of our other cables, better tone, and just overall better in every way. Guess what cable I always buy now?

I'm not one who is big on 'boutique' parts but sometimes someone does have a better idea!
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Old 4th April 2007, 10:57 PM   #7
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Hey Sherman, I'm curious, what is the cable itself? Assuming they bought coax from Belden/etc it should say right on the cable.

-- Dave
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Old 4th April 2007, 11:10 PM   #8
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Hi,

Gabe, I'm glad your ears have convinced you, good on you.

Now should anyone feel the need to drive long cable lengths into small Zin amps, capacitance increases over length as you all know, whilst being able to adjust volume at the same time, nothing beats a quality attenuator of highish impedance (50 to 500K is fine depending on Zout of your source) followed by a White CF. The schematic is on the forum....Somewhere anyway.

As for thin wires, I'd recommend 0.6mm or even 0.4mm depending on the current that needs to pass.

Skineffect not audible, huh?

Cheers,
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Old 5th April 2007, 01:01 PM   #9
Sherman is offline Sherman  United States
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Quote:
Originally posted by Dave Cigna
Hey Sherman, I'm curious, what is the cable itself? Assuming they bought coax from Belden/etc it should say right on the cable.

-- Dave

Dave,

The cable itself is printed "Planet Waves" and nothing else so I don't know who manufactures it. It is relatively heavy with really nice rubber insulation on it and it is quite flexible.

Another thing- it is directional cable. One end is supposed to go into the guitar and the other end into the amp/mixer/effects pedal, whatever. And yes, the difference is audible when the cable is used the other way 'round.

IIRC the cable is actually not regular coax. It has two signal wires, signal and ground which connect to the tip and body of the quarter inch jack. Both of those wires are then inside a braided shield which is apparently and correctly grounded at only one end (hence, I believe, the directional quality of the cable).

In any case they make a positive audible difference in the sound. Plus that cool quarter inch connector makes really solid contact regardless of how worn or out-of-spec your quarter inch jack is.
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Old 5th April 2007, 01:12 PM   #10
phn is offline phn  Sweden
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The cable is semi- or quasi-balanced. There's really nothing balanced about it. But...

Wire is not directional. The shield is grounded in one end, is all. It's a standard microphone cable.
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