Anyone want a Adcom GFP 555 II

[arcorob]

Okay, no not giving away or selling but using it as a pre-amp to test against my Marantz pre - it lost miserably

I set it up in my rig with the Adcom as the pre and my normal Velleman tube amp as power

First test was Vinyl of course because I felt that before, it was stellar and did not want to lose that to gain something in streaming. It did have a wide field soundstage but thats all the good I could say about it. It was harsh and while some might call it clarity, it rounded no edges and was brash.

So went over to try streaming. It was "ok" but again, was better before on the marantz SR 4023.

I know some people really like the Adcom and as I have learned, sychronicity of sound is really dependent on all parts in the rig. This was not a match.

I will say this, it was a very clean, fully operating unit and the inside looked like it just left the factory

(2) The inside of ADCOM GFP 555 II - Very clean - YouTube

 

[BMWCCA]

When people mention Adcom, they are mostly talking about the power amps. I own a GTP-450 and it works fine paired with a GFA-535L. Nothing remarkable but it does its job. To be quite honest, you shouldn't really "hear" a pre-amp. My Crown "Straight Lines" know that. And my Soundcraftsmen Pro-Control-Fours have loops and bypasses to make sure the pre does not change the sound from the source. I feel you should be able to take any good pre-amp and put it in any system and . . . ideally the sound from the speakers will not change.

 

[arcorob]

When people mention Adcom, they are mostly talking about the power amps. I own a GTP-450 and it works fine paired with a GFA-535L. Nothing remarkable but it does its job. To be quite honest, you shouldn't really "hear" a pre-amp. My Crown "Straight Lines" know that. And my Soundcraftsmen Pro-Control-Fours have loops and bypasses to make sure the pre does not change the sound from the source. I feel you should be able to take any good pre-amp and put it in any system and . . . ideally the sound from the speakers will not change.

You are correct that they SHOULD not yet; they often do. The Adcom as I understand is a special snowflake and before buying I was hesitant because I saw people either LOVED it or HATED it..no middle ground...LOL. Again, I beleive that there is a syncronicity of sound among devices where for example, you hook up speakers to one system and say UGGGG...put them on another and AHHHH...It has talen me a long time to ensure my systems are MUCH closer to AHHH...My next trial will be the Wiim Pro to see how that sounds into the system vs my direct connect with Ipad or Fire. It may be better, worse or indifferent but willing to try.

I will tell you this. I added Bluetooth to my somewhat over the top garage rig...So I could stream to a Marantz 2220B. Now I could direct connect but this allowed me to be "untethered". I tell you this adapter is flawless. No drops, no noise, and very automatic. for $22 how hard was the decision to try ? LOL

Amazon.com: [Upgraded] 1Mii B06 Plus Bluetooth Receiver, HiFi Wireless Audio Adapter, Bluetooth 5.1 Receiver with 3D Surround aptX HD aptX Low Latency for Home Music Streaming Stereo System : Electronics

 

[grillebilly]

When people mention Adcom, they are mostly talking about the power amps. I own a GTP-450 and it works fine paired with a GFA-535L. Nothing remarkable but it does its job. To be quite honest, you shouldn't really "hear" a pre-amp. My Crown "Straight Lines" know that. And my Soundcraftsmen Pro-Control-Fours have loops and bypasses to make sure the pre does not change the sound from the source. I feel you should be able to take any good pre-amp and put it in any system and . . . ideally the sound from the speakers will not change.

I'm not going to debate it but you will likely get some blowback saying a pre doesn't color the music somewhat. Especially from tube guys who are extolling the virtues of "warmth" and tube rolling in their preamps. Lots of us here think SS power and tube preamps are the ticket.
I have no dog in the fight so this post wasn't intended to be combative.
Carry on.

 

[painttoad]

When people mention Adcom, they are mostly talking about the power amps. I own a GTP-450 and it works fine paired with a GFA-535L. Nothing remarkable but it does its job. To be quite honest, you shouldn't really "hear" a pre-amp. My Crown "Straight Lines" know that. And my Soundcraftsmen Pro-Control-Fours have loops and bypasses to make sure the pre does not change the sound from the source. I feel you should be able to take any good pre-amp and put it in any system and . . . ideally the sound from the speakers will not change.

i don't really like my gtp-450 that much. pretty blah sounding to me.i bet in a blind test with my other pre amps, i could pick it out.(and they are all about the same price point) i knew adcom pres were nothing special when i bought it.

 

[justjed2]

My GTP-500 has been in a closet for a decade because I much prefer my tube-hybrid pre.

 

[Mrv8q]

On the flip side…

I have a 555 doing ‘workhorse’ duty as the hub for a simple computer system, tied to an Adcom 575 CD player. For what I use it for in this situation, it works fine and has for 30 years. I don’t listen to it critically in this regard, but, that’s ok.

Maybe time has marched on for the Adcom, but I appreciate it always powering on.

 

[BMWCCA]

I'm not going to debate it but you will likely get some blowback saying a pre doesn't color the music somewhat. Especially from tube guys who are extolling the virtues of "warmth" and tube rolling in their preamps. Lots of us here think SS power and tube preamps are the ticket.
I have no dog in the fight so this post wasn't intended to be combative.
Carry on.

No debate. The same people who prefer a tube front-end will likely endlessly "roll" tubes to create the sound they want. They don't want "straight-line" reproduction. I have owned a great tube pre (Mac C20) for over 50-years. I always loved the sound with my range-challenged JBL 030s and LPs back then. Today if I need to modify the sound of my source it's usually because I don't like the mix the engineer did. For that I use my "straight-line" pre and put a third-octave EQ in there. Alternately I can always throw a blanket over the speakers to emulate that tube and vinyl sound.

 

[arcorob]

So - THIS "Alternately I can always throw a blanket over the speakers to emulate that tube and vinyl sound." is NOT funny at all

So pre-amps, EQ'sanytjing between the source and the POWER amp has a sound. You cant get away from it simply because all the power amp does (or should do) is amplify a line level signal - Now with a preamp unless you defeat tone controls , right there you have coloration in a signal. Then there is what technology is in there, caps , etc. Now, move on to the power amp - That too will have a sound (more so with Tube amps like mine where I puposely refined and rolled tubes to my version of perfection).

Even high end experts who never thought that it made a difference change their minds...Proof below

 

[C Hart]

I do not think that guy is any kind of authority. Sorry. Preamps should never have a “sound”.

 

[MuseChaser]

The Adcom GFP565 is a whole 'nuther beast, with a great phono section. An excellent preamp.

 

[arcorob]

I do not think that guy is any kind of authority. Sorry. Preamps should never have a “sound”.

Sorry to disagree, but you are 100% incorrect in that what they SHOULD vs what they do is two different things. The ability to pass through a signal without any flucuation (coloration of sound) is less than 5%. They are built to completely bypass all circuits that would do that but that is not standard at all. Its uncommon

Example - Here is a pre-amp that falls all over itself to not colorize sound - LT-6P Preamplifier (wrightaudioarts.com)
Then anyone with a brain says - Ummm.tubes ...Those tubes selected will have a sound and changing those tubes will change that sound. That sound may be optimized for that device but if they are in the path, they add a sound. Hell, your source devices have a sound.

So lets take tubes out of that equation. How many preamps in a semi reasonable budget DONT have a sound, clean straight signal path ? Ummm...none. Otherwise, if that was common, why have it at all ? Just run a signal switch for inputs to a power amp and every preamplifier section would be universal -- Like a USB thumb drive

Oh and the owner of PS Audio is not an authority ??? LOL

 

[BMWCCA]

Let us go back the the beginning of our hobby. Back when it was called "High Fidelity". The point of any system is to faithfully reproduce the recording or source without intentionally changing it. Tone controls, tube-rolling, unintended consequences that affect the sound are not ideal. Having a perfect "straight wire" response then leaves you with the ability to add tone controls, EQ, whatever you like. But to be Faithful to the recording only happens if there is no coloration. You can like the sound of one pre over the other just like you can like the sound of one speaker over another. But the point of a pre-amp isn't to create a Kodachrome enhancement of reality. If that's what you like, then that's fine, too. Often it's the same people who look down on any pre-amp with tone controls, who roll tubes to create a sound. This is not just semantics. True Fidelity only happens if the character of the recording is not altered in any way. But then we may hate the balance that was engineered into the original recording, or our room response may suck. But it you start out with a certain tone to your pre-amp, your intent may not be fidelity. Have you tried the "blanket" solution to the digital vs analog argument?

 

[arcorob]

Let us go back the the beginning of our hobby. Back when it was called "High Fidelity". The point of any system is to faithfully reproduce the recording or source without intentionally changing it. Tone controls, tube-rolling, unintended consequences that affect the sound are not ideal. Having a perfect "straight wire" response then leaves you with the ability to add tone controls, EQ, whatever you like. But to be Faithful to the recording only happens if there is no coloration. You can like the sound of one pre over the other just like you can like the sound of one speaker over another. But the point of a pre-amp isn't to create a Kodachrome enhancement of reality. If that's what you like, then that's fine, too. Often it's the same people who look down on any pre-amp with tone controls, who roll tubes to create a sound. This is not just semantics. True Fidelity only happens if the character of the recording is not altered in any way. But then we may hate the balance that was engineered into the original recording, or our room response may suck. But it you start out with a certain tone to your pre-amp, your intent may not be fidelity. Have you tried the "blanket" solution to the digital vs analog argument?

I dont disagree with what you are saying in theory but in practice its just not so. Again I point out why does a person choose preamp A vs Preamp B ? Even if the reason is A more faithfully reproduces the original sound , that alone tells you there is a difference. Thats why there are so many brands. If A and B were identical, then why have more than one brand ? Why add tone controls to some and not others ? Alot of this is regulated by price point also. I dont want to debate this as everyone will have their opinions. All I know is my Marantz SR4023 is more pleasing as a pre-amp than the Adcom. And really , isnt that all that matters ?

 

[MuseChaser]

.... All I know is my Marantz SR4023 is more pleasing as a pre-amp than the Adcom. And really , isnt that all that matters ?

It's more "pleasing" to you, and that's all that matters to you. There are many preamp (and any other component) choices for a myriad of reasons, not the least of which is that what may please one person may not please another. Some desire features and flexibility. Some desire simplicity. Some like euphonic treatment of source material. Some value fidelity to the source. Some value frugality. Some folks have unlimited budgets.

Personally, I think choosing a component based upon it having its own unique tonal coloration is... well... unproductive, anyway. Use tone controls to correct poor source material if desired, sure, but having a component be a "permanent" tone control won't serve all source material equally well.

I don't want to hear ANY of my components. I want to hear the source.

 

[JoeESP9]

I've had a couple of Adcom preamps. IMO the only one worth buying or having is the GFP-750. OTOH I use a pair of GFA-545's to drive my surround speakers. They are Acoustat Model 1's with a dual passive subwoofer (Acoustat SPW-1) the signal is split via an electronic crossover.

 

[C Hart]

Sorry to disagree, but you are 100% incorrect in that what they SHOULD vs what they do is two different things. The ability to pass through a signal without any flucuation (coloration of sound) is less than 5%. They are built to completely bypass all circuits that would do that but that is not standard at all. Its uncommon

Example - Here is a pre-amp that falls all over itself to not colorize sound - LT-6P Preamplifier (wrightaudioarts.com)
Then anyone with a brain says - Ummm.tubes ...Those tubes selected will have a sound and changing those tubes will change that sound. That sound may be optimized for that device but if they are in the path, they add a sound. Hell, your source devices have a sound.

So lets take tubes out of that equation. How many preamps in a semi reasonable budget DONT have a sound, clean straight signal path ? Ummm...none. Otherwise, if that was common, why have it at all ? Just run a signal switch for inputs to a power amp and every preamplifier section would be universal -- Like a USB thumb drive

Oh and the owner of PS Audio is not an authority ??? LOL

Well, the gauntlet has been thrown I guess.

Which was 100% wrong? Was it my assertion that preamps should never have a sound?

Audio is the physics of waves and electrons. The ability to pass a signal without distortion in a modern solid state circuit preamp design is nearly 100% (99.99 in the case of .01% THD).

Tubes generally have color. Some like that and that is fine. I like accuracy and fidelity to the original signal. And yes, I think almost every solid state preamp does exactly what I said, passing the signal with minimal and inaudible levels of distortion and color.

Or was it my opinion that the PS Audio guy is not an authority?

Those videos are simply advertisements for his philosophy, which, by extension, is a giant ad for his products. Like all ads they have germs of truth along with huge doses of marketing. As usual, I found no basis for any conclusions in the video with the exception of his assertion (paraphrase) "I liked it." Show me any test in which even a discerning listener can hear fractions of a percentage of distortion.

 

[arcorob]

Well, the gauntlet has been thrown I guess.

Which was 100% wrong? Was it my assertion that preamps should never have a sound?

Audio is the physics of waves and electrons. The ability to pass a signal without distortion in a modern solid state circuit preamp design is nearly 100% (99.99 in the case of .01% THD).

Tubes generally have color. Some like that and that is fine. I like accuracy and fidelity to the original signal. And yes, I think almost every solid state preamp does exactly what I said, passing the signal with minimal and inaudible levels of distortion and color.

Or was it my opinion that the PS Audio guy is not an authority?

Those videos are simply advertisements for his philosophy, which, by extension, is a giant ad for his products. Like all ads they have germs of truth along with huge doses of marketing. As usual, I found no basis for any conclusions in the video with the exception of his assertion (paraphrase) "I liked it." Show me any test in which even a discerning listener can hear fractions of a percentage of distortion.

I am actually done with debating you. You insist on theory where I am a practical analyst living in reality. Glad you have a system with no color and you enjoy it. And I will take PS Audio refrences over your sillyness any day - Oh and by the way , maybe Check out their BK series which was created by one of the finest amp designers EVER. He insisted, it must have tubes. And in A-B blind tests, his design blew away a MOSFET design . Let me also point out that you are confusing THD with coloration - Sorry, not the same . Music and listening is more than just some a set of eletrons. You need to present them in a way to please the listener or as I pointed out, there would be one brand, one design and no one would deviate from it. On to better posts.....

EDIT - Had to add this since you dont seem to understand audio, which is better in a signal path - Electrolytic caps or non-polarized film ? Why would you use one over the other? If its about THD as you say then anything using electrolytics in a signal path must be garbage right ? Yet, the majority of amps do ...and many dont ...in each case, there will be a difference in sound. So if both units had the same exact THD , how do you account for the difference ? Because there would be a diffence.

 

[MuseChaser]

.....
, which is better in a signal path - Electrolytic caps or non-polarized film ? .

It depends.

... Why would you use one over the other? .

Purpose of that portion of the circuit. Critical part of signal path...or power supply...or? Size. Reliability. Cost. All kinds of reasons.

... If its about THD as you say then anything using electrolytics in a signal path must be garbage right ? Yet, the majority of amps do ...and many dont ...in each case, there will be a difference in sound. So if both units had the same exact THD , how do you account for the difference ? Because there would be a diffence.

The makeup of THD (odd vs even order harmonics - typically quite different between tubes and solid state, even leaving out the higher amount typical of tube designs). Amount of TIM. Slew rate. Frequency response. Available current/ability to drive difficult loads. Rejection of interference/crosstalk. S/N ratio.

You like the way your choices sound, and that's fine. To some folks, including me, the pursuit of "high fidelity"reproduction IS more about the old "straight wire with gain...".. fidelity to the source. No need for you to take offense to that. If we are not being faithful to the source, but are rather coloring it to our preference, then to what exactly IS the "fidelity" in "high fidelity" referring?

 

[N8Nagel]

I am using a GFP-555ii in my bedroom right now and don't find it offensive, but my understanding is the GFP-565 is the one to have if you like Adcom. However the price was right and it works. I am currently feeding a Dynaco ST-120 with it as both of the Adcom amps that came with the GFP have issues and I haven't had time to deal with them.