Adcom Passive pre vs active

Mr. Bubbles

I have been curious lately about using a passive pre-amp. i currently use the Adcom GFA-565 in my main 2 ch rig. This is used in conjunction with an Adcom GFA555II and SRS 1.2TL's. I understand the GFA750 to be either passive or active depending on user selection of this function. Adcom also made an SLC unit which is strictly passive. I know the 750 is very highly regarded. But is this for the passive operation or its active operation or due to it being selectable for use either way? Is the SLC unit good as a passive unit? And lastly am I wasting my time considering this?

I have no experience with any passive pre's and am historically used to the Adcom gear I have mentioned above along with carver C-1 and 4.0T, C-2 and 1.0 some Macintosh gear and mostly Vintage Marantz pre's like the 7T, 3250 and some other Marantz integrated in other systems i have through the house. For general listening I usually prefer the sound of the vintage marantz gear but find the bass end a little loose for the Polks. I am trying to determine if i may like the passive pre's or not. I know my ears will naturally be the best judge in the end. I do prefer the Adcom gear best for critical listening, of all my other gear.

soundfreak1

I have a slc 505 ( used primerily) as a straight line controler, have user spairingly as a pre and i must say it is the only adcom pre i have listeded to that i have cared for. Never heard the 750 but i have seen good reviews on it, having said that. I never cated for the 400 & 600 series that i have had. Did not like the way they " colored" yhe sound especially the highs and base notes they seemed harsh on the highs and boomy in the base to me. Just mho. The 505 is much more neutral but if i were to use it as a pre full time i would upgrade the volume control.

audiocr381ve

Mr. Bubbles wrote: »

I have been curious lately about using a passive pre-amp. i currently use the Adcom GFA-565 in my main 2 ch rig. This is used in conjunction with an Adcom GFA555II and SRS 1.2TL's. I understand the GFA750 to be either passive or active depending on user selection of this function. Adcom also made an SLC unit which is strictly passive. I know the 750 is very highly regarded. But is this for the passive operation or its active operation or due to it being selectable for use either way? Is the SLC unit good as a passive unit? And lastly am I wasting my time considering this?

I have no experience with any passive pre's and am historically used to the Adcom gear I have mentioned above along with carver C-1 and 4.0T, C-2 and 1.0 some Macintosh gear and mostly Vintage Marantz pre's like the 7T, 3250 and some other Marantz integrated in other systems i have through the house. For general listening I usually prefer the sound of the vintage marantz gear but find the bass end a little loose for the Polks. I am trying to determine if i may like the passive pre's or not. I know my ears will naturally be the best judge in the end. I do prefer the Adcom gear best for critical listening, of all my other gear.

Hey bubbles,

The 750 is legendary because of the passive section. It's awesome. Natural, organic, smooth, musical. Good passive pres are only as good as the source. They'll pass along what ever signal your source is giving them. IMO if you're a little shaky on your source, you might want to take care of that first. The Channel Islands VDA-2 is a wonderful DAC that I'm using, I mean, astounding musical sound from my digital music library.

GlennDog

Old post, but this is exactly what I was contemplating today, so . . . Bump!

voltz

WOW Glen I would think you will have a tough time finding something as good as your Cary. I've never heard one to really say but...

tonyb

Glen,
Contemplating switching out the Cary slp for the Adcom ??

Don't....chalk that thought up to bad cheese.

GlennDog

No, the Cary is not going anywhere anytime soon. I was just thinking in general terms, Meaning, if there is less in the signal path, that would offer more accurate SQ

This article is what got me thinking about passive vs. active pre amps

http://www.tortugaaudio.com/what-is-a-passive-preamplifier/

tonyb

One thing I've learned in audio over the years is to take certain science with a grain of salt. On paper, some things look good but in practice there's just too many variables that affect the sound.

That said, I've heard some darn good passives....the Dodd's come to mind, but also a lot of stinkers too. Some seem to suck the musicality right out. I wouldn't go out of my way for a passive pre unless it had solid track records of users singing it's glory. Then again, that can be said for any piece of gear.