Old versus New

[Ken Pachkowsky]

Hi Guys, hope your all well.

I wanted to share a recent experience of mine. This is not meant to knock anything but is just MHO.

I have been using an Apt Holman pre-amp for the last couple of years and have been very happy with it. A friend recently bought an Adcom GFP 750 and was literally blown away by its performance which in turn got me interested in trying one myself.

I purchased a unit off Ebay and was very excited to try it out.
My initial impressions were mixed but I felt it would require some tweaking to get it dialed in. I have spent the last few weeks trying many different settings and combinations to get this right. It sounded best in passive mode.

IMHO the bottom line is this:
The 25 year old Apt Holman has far better depth of soundstage and imaging. In terms of frequency range the Adcom sounds great. A kick drum sounds like it should, a snare snaps, vocals are sharp and clear, but it all sounds “one dimensional”.

With the Apt Holman you can swear the sound is coming from somewhere other than the speakers. Many times I have found myself staring at the left or right monitor and being amazed that the sound does not appear to be coming from that monitor but off in the distance behind the monitors with the occasional hint of a left and right.

With the Adcom this is not the case. For the most part there is a definite left and right and the sound is clearly coming from that monitor.
In short, on my system I much prefer the Old Technology.

However, I can not be sure there is no problem within the Adcom’s electronics.

Have a good day.

For Sale
1 Adcom 750 in excellent condition (I think).

[Earl K]

- Interesting ,,, I find that all sorts of dramatic changes to "imaging or the depth of sound-stage" can result from small, seemingly insignificant parts swaps.


<. Earl K :D

( Shouldn't this thread be in the "Off-Topic" area ? :blink: )

[Ken Pachkowsky]

( Shouldn't this thread be in the "Off-Topic" area ? :blink: )

<. Earl K :D

Hmm. I do believe you are right....Can I change that?

Ken

[10 Watt Street]

Ken,
I have found the Adcom GFP-750 to be quite excellent, once I quit overdriving it. Though it has a set of balanced inputs and outputs, they are for the consumer -10 level, rather than the pro +4 standard.

I was using an Apogee D/A into the balanced input and was overdriving the Adcom. The Apogee has a +4/-10 output level switch on the back panel and that solved everything.

If you have little usable range on the volume control and don't like what you hear, you might look into it.

[Ken Pachkowsky]

Ken,
I have found the Adcom GFP-750 to be quite excellent, once I quit overdriving it.

If you have little usable range on the volume control and don't like what you hear, you might look into it.

Interesting, you have me wondering.

Let me try something.

Ken

[Ken Pachkowsky]

I am going to admit something here that is difficult so others can learn from it. I have switched around things on a complicated eight amp 4-way system so much in the last few weeks that sometime in the last week I inadvertently had the HF and UHF horns switched left and right. Having done this so many times it could be done in my sleep, I was too arrogant to check for a mistake that only rookies make.:blah:

In short, turning down the outputs on the 4400's combined with correcting the horn L-R problem has improved things to the point I will run the RTA setup again to see if the corrections will change my mind on this Adcom. Embarrassing to say the least!

10 Watt Street
Thanks for the nudge and reminding me the outputs are adjustable on the 4400's.

Check, Check and Double Check

[Robh3606]

Hey Ken

We have all done stuff like that:biting: . One of the reasons I hate messing with my main set-up. I always get something out of phase or swapped. It's like a right of passage and the price you pay for not keeping things simple:D. I even get Left and Rights on my CD player swapped! Go figure

Rob:)

[Ian Mackenzie]

I am going to admit something here that is difficult so others can learn from it. I have switched around things on a complicated eight amp 4-way system so much in the last few weeks that sometime in the last week I inadvertently had the HF and UHF horns switched left and right. Having done this so many times it could be done in my sleep, I was too arrogant to check for a mistake that only rookies make.:blah:

In short, turning down the outputs on the 4400's combined with correcting the horn L-R problem has improved things to the point I will run the RTA setup again to see if the corrections will change my mind on this Adcom. Embarrassing to say the least!

10 Watt Street
Thanks for the nudge and reminding me the outputs are adjustable on the 4400's.

Check, Check and Double Check

You idiot,

You nearly all had us selling our Adcoms on Ebay.:blah: :bs:

[Ken Pachkowsky]

You idiot,

You nearly all had us selling our Adcoms on Ebay.:blah: :bs:


HaHa Ian. Never mind making jokes and get back to work!
:rotfl:

[boputnam]

...I have switched around things on a complicated eight amp 4-way system so much in the last few weeks... Hey...

I know we've pm'd about some of this - I'm not sure if this is new, or the same issues.

Oldmics and I have really complicated roadracks - mine certainly much less a monster than any of his! - and labelling and knowing the signal path is the only way to stay sane. In my (admittedly small) set-up, on New Years Eve I counted over 168 connections that have to be made EXACTLY right, or I'll get a beer hurled at me - from the lead guitar player!! And, I have to get it done in less than 60-minutes, including load-in. Labelling, labelling, labelling. And, planning, planning, planning.

I carry the same mantra into the home, where although much simpler, there are plenty opportunities to get it wrong.

I've not seen the latest incarnation, and surely it's complicated, but some of your symptoms might be signal-path related, indeed. Misdiagnosis is an awful frustrating row to hoe...

But hell - I've bought some of my most favorite gear off your upgrades, so keep pushing the envelope!! :rotfl:

[Ian Mackenzie]

HaHa Ian. Never mind making jokes and get back to work!
:rotfl:

A joke correct but time you took a break.

I agree with Bo, multi way systems can easily lead to confusion and incorrect assumptions.

May I suggest colour coded leads or multi pole Speakon connectors,and keep a log of the changes you make. Its easy to forget what was previously if you don't keep a record. You could also buy a Roadie electronic pocket knife, a gadget that checks these errors incl phase integrity.

This stuff can easily send you goggle eyed so take a break from it all.

Ian

[Ken Pachkowsky]

A joke correct but time you took a break.

This stuff can easily send you goggle eyed so take a break from it all.

Ian

I have no choice about the break, its off to Oklahoma City and Sacremento starting next week. Will not get a chance to putter around till February. Back to work for this guy.

I just built all new neutrik xlr cables and ran out of colored tape to code the ends.....should have taken the time to go a get some more. Lesson learned and for the record, the jury is still out.

Ken

[boputnam]

"When in doubt, turn off some amps and simply walk the room..."

[boputnam]

Hey, Don...

During Ken's absence, mayhaps move this thread to "Off Topic"?
credits to Earl K <>