Adcom GFP-750 Back in the System

audiocr381ve
audiocr381ve Posts: 2,588
edited April 2012 in 2 Channel Audio
Well, I sold this piece over a month ago and the buyer had a problem with the active section while the passive was working perfectly. So it arrives today and I'm not able to recreate the problem. A.K.A., it's working perfectly for me. I'm still going to refund the buyer of course.

Anyway, this thread isn't about that. I was just about to give up on the CRS+'s lately because they just weren't doing it for me connected to my vintage Marantz 1150 integrated. Sure enough I put the GFP-750 back in the mix and the speakers are lovely again. What a difference this thing makes across the entire frequency range. Now I'm hearing bass, punch, clarity, just wow....

Just wanted to share how happy I am again :)
Post edited by audiocr381ve on
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  • heiney9
    heiney9 Posts: 25,171
    edited April 2012
    I enjoy saying "I told you so" over and over.......:razz:

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
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  • audiocr381ve
    audiocr381ve Posts: 2,588
    edited April 2012
    heiney9 wrote: »
    I enjoy saying "I told you so" over and over.......:razz:

    H9

    Hehe, you know I love you! :P
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  • polkfarmboy
    polkfarmboy Posts: 5,703
    edited April 2012
    Will you be selling it again ?
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  • hochpt21
    hochpt21 Posts: 5,423
    edited April 2012
    I think he wants to be reunited with his brother.:wink:
    2 ChannelTurntable - VPI Classic 2/Ortofon 2M BlueAmplification - Rogue Audio Cronus Magnum II, Parks Audio Budgie PhonoSpeakers - GoldenEar Triton 17.2 Home TheaterDenon AVR-X3300W; Rotel RMB-1066; Klipsch RP-280F's, Klipsch RP-450C, Polk FXi3's, Polk RC60i; Dual SVS PB 2000's; BenQ HT2050; Elite Screens 120"Man CaveTurntable - Pro-Ject 2.9 Wood/Grado GoldAmplification - Dared SL2000a, McCormack DNA 0.5 DeluxeCD: Cambridge AudioSpeakers - Wharfedale Linton 85th Anniversary; LSiM 703; SDA 2A
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  • audiocr381ve
    audiocr381ve Posts: 2,588
    edited April 2012
    polkfarmboy wrote: »
    Will you be selling it again ?

    I've lost her once, I won't let it happen again :)
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  • chandler9a
    chandler9a Posts: 878
    edited April 2012
    nice! I am looking for one constantly these days. Glad to hear its back where it belongs.
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  • audiocr381ve
    audiocr381ve Posts: 2,588
    edited April 2012
    chandler9a wrote: »
    nice! I am looking for one constantly these days. Glad to hear its back where it belongs.

    Thanks Aaron!
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  • steveinaz
    steveinaz Posts: 19,538
    edited April 2012
    I've sold many things I've later regretted, at least you got'er back!
    Source: Bluesound Node 2i - Preamp/DAC: Benchmark DAC2 DX - Amp: Parasound Halo A21 - Speakers: MartinLogan Motion 60XTi - Shop Rig: Yamaha A-S501 Integrated - Shop Spkrs: Elac Debut 2.0 B5.2
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  • audiocr381ve
    audiocr381ve Posts: 2,588
    edited April 2012
    steveinaz wrote: »
    I've sold many things I've later regretted, at least you got'er back!

    Yea seriously!
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  • steveinaz
    steveinaz Posts: 19,538
    edited April 2012
    That's a very respectable preamp, considered it many times myself. I'm not surprised you like it.
    Source: Bluesound Node 2i - Preamp/DAC: Benchmark DAC2 DX - Amp: Parasound Halo A21 - Speakers: MartinLogan Motion 60XTi - Shop Rig: Yamaha A-S501 Integrated - Shop Spkrs: Elac Debut 2.0 B5.2
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  • thsmith
    thsmith Posts: 6,082
    edited April 2012
    Are you using the Marantz 1150 as an amp now?
    Speakers: SDA-1C (most all the goodies)
    Preamp: Joule Electra LA-150 MKII SE
    Amp: Wright WPA 50-50 EAT KT88s
    Analog: Marantz TT-15S1 MBS Glider SL| Wright WPP100C Amperex BB 6er5 and 7316 & WPM-100 SUT
    Digital: Mac mini 2.3GHz dual-core i5 8g RAM 1.5 TB HDD Music Server Amarra (memory play) - USB - W4S DAC 2
    Cables: Mits S3 IC and Spk cables| PS Audio PCs
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  • cnh
    cnh Posts: 13,284
    edited April 2012
    I've been eyeing these for quite some time. One is definitely on the "agenda"!

    Glad you got yours back! Hard to beat price/performance wise.

    cnh
    Currently orbiting Bowie's Blackstar.!

    Polk Lsi-7s, Def Tech 8" sub, HK 3490, HK HD 990 (CDP/DAC), AKG Q701s
    [sig. changed on a monthly basis as I rotate in and out of my stash]
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  • audiocr381ve
    audiocr381ve Posts: 2,588
    edited April 2012
    thsmith wrote: »
    Are you using the Marantz 1150 as an amp now?

    Yea I am believe it or not. I'll be using it this way for awhile. I'm pretty much listening near-field these days and definitely don't need anymore power.
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  • chandler9a
    chandler9a Posts: 878
    edited April 2012
    Shane, I saw another thread you started on this preamp where you guys were talking about the jumpers that should be on the back of this unit for some reason. Do you remember where to get those if they do not come with the unit? I tried to find to thread but had no luck... I seem to remember there was some sort of website with them for sale, maybe H9 will chime in.

    Thanks
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  • heiney9
    heiney9 Posts: 25,171
    edited April 2012
    chandler9a wrote: »
    Shane, I saw another thread you started on this preamp where you guys were talking about the jumpers that should be on the back of this unit for some reason. Do you remember where to get those if they do not come with the unit? I tried to find to thread but had no luck... I seem to remember there was some sort of website with them for sale, maybe H9 will chime in.

    Thanks

    http://www.dedicatedaudio.com/inc/sdetail/5157

    These are very nice and won't break the bank. They are standard XLR shorting pins, so they can be used for any std XLR input.
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
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  • chandler9a
    chandler9a Posts: 878
    edited April 2012
    That's what I was looking for, thanks! From the photos of the unit I bought, I didn't look like they were there...
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  • heiney9
    heiney9 Posts: 25,171
    edited April 2012
    chandler9a wrote: »
    That's what I was looking for, thanks! From the photos of the unit I bought, I didn't look like they were there...

    They need to be used for the balanced cd input if they are missing. If they are missing the single ended inputs will not sound right. Shorting pins aren't needed for the XLR output of the pre-amp.

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
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  • audiocr381ve
    audiocr381ve Posts: 2,588
    edited April 2012
    heiney9 wrote: »
    They need to be used for the balanced cd input if they are missing. If they are missing the single ended inputs will not sound right. Shorting pins aren't needed for the XLR output of the pre-amp.

    H9

    So you picked one up Aaron?

    Brock, I just got a message from the buyer who returned the GFP-750 to me. He said the balanced input was NOT working in active mode. He was using both the balanced input and balanced output when it happened. Do you know what could have been going on?
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  • audiocr381ve
    audiocr381ve Posts: 2,588
    edited April 2012
    Direct quote about the problem:
    I was using the balanced input and outputs. I never checked the others. I opened the top to switch the jumpers to set it for balanced. When I relealized the active wasnt working I removed the top and wiggled all the connectors. Thats all I have done. The active mode would work sometimes but never for long.
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  • heiney9
    heiney9 Posts: 25,171
    edited April 2012
    Ummm....not sure why he "opened the top" to switch jumpers. There is nothing internal to switch. The shorting plugs go into the actual holes of the balanced input to short them so when you use the single ended inputs the gain is correct. There is no reason to open the top and all the switching is done by relay so I'm not sure what he was "wiggling". If he was in fact using the balanced inputs and outputs then the shorting pins have no relevance of effect.

    See this thread for close up of the internals.

    ADCOMGFP-750003.jpg
    ADCOMGFP-750007.jpg
    ADCOMGFP-750stock009.jpg

    If it works fine for you in passive and active then I'd say he had other issues or somehow had it hooked up wrong......although it's not difficult to hook-up unless you are Polkfarmboy who couldn't get Chris's(csmstar01) to play right nor could the repair shop find anything wrong with it.

    I guess I could see you buyer maybe wiggling the ribbon cable shown in the last photo that goes from the front panel switched to the board, but other than that nothing in there to flip or wiggle. All the source switching is handled by the bank of white Siemens relays at the back of the unit and that has nothing to do with the active/passive status.
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
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  • audiocr381ve
    audiocr381ve Posts: 2,588
    edited April 2012
    Very strange. I know for a fact the balanced outputs work. I used them when I had the B&K 200.2 hooked up. I never used the balanced inputs but I'm trying to get my hands on something to test it out. I wonder if plugging a microphone into one of the balanced inputs would work for testing purposes?
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  • heiney9
    heiney9 Posts: 25,171
    edited April 2012
    I don't know, the impedance might be a mismatch. I guess I didn;'t understand that you never used the balanced input. Perhaps there is an issue, but I would think the same issue would manifest itself even when the jumpers are in place and using the single ended cd input. Obviously the signal path goes throught the balanced circuitry otherwise the jumpers wouldn't be needed.

    But you are saying the balanced doesn't work with active, only passive? That's probably a different issue. Maybe look at DIYAUDIO.COM and see if someone else had an issue like that.

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
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  • audiocr381ve
    audiocr381ve Posts: 2,588
    edited April 2012
    heiney9 wrote: »
    I don't know, the impedance might be a mismatch. I guess I didn;'t understand that you never used the balanced input. Perhaps there is an issue, but I would think the same issue would manifest itself even when the jumpers are in place and using the single ended cd output. Obviously the signal path goes throught the balanced circuitry otherwise the jumpers wouldn't be needed.

    But you are saying the balanced doesn't work with active, only passive? That's probably a different issue. Maybe look at DIYAUDIO.COM and see if someone else had an issue like that.

    H9

    No I'm saying the buyer said that, I haven't had a chance to test the balanced inputs. Everything else is working perfectly in both passive and active mode. I'll take a looksy over there, thanks Brock.
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  • chandler9a
    chandler9a Posts: 878
    edited April 2012
    audiocr381ve wrote: »
    So you picked one up Aaron?

    Yup! found one on the Gon for a decent price and in really good condition from what it looked like. On its way to me from your side of the country as we speak.
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  • audiocr381ve
    audiocr381ve Posts: 2,588
    edited April 2012
    audiocr381ve wrote: »
    So you picked one up Aaron?

    Yup! found one on the Gon for a decent price and in really good condition from what it looked like. On its way to me from your side of the country as we speak.

    Rad dude! You're in for a real treat. Love this thing. I do want to add tubes again eventually, but this is such a solid piece.
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  • heiney9
    heiney9 Posts: 25,171
    edited April 2012
    chandler9a, you could have waited a few weeks and I'm sure audiocr381ve would have his up forsale. :razz:

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
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  • FTGV
    FTGV Posts: 3,649
    edited April 2012
    audiocr381ve wrote: »
    ... I just got a message from the buyer who returned the GFP-750 to me. He said the balanced input was NOT working in active mode. He was using both the balanced input and balanced output when it happened. Do you know what could have been going on?
    Miight his source have a switch to enable bal output that was'nt engaged?
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  • audiocr381ve
    audiocr381ve Posts: 2,588
    edited April 2012
    heiney9 wrote: »
    chandler9a, you could have waited a few weeks and I'm sure audiocr381ve would have his up forsale. :razz:

    H9

    As a full-time freelancer, that might end up happening again!
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  • audiocr381ve
    audiocr381ve Posts: 2,588
    edited April 2012
    FTGV wrote: »
    Miight his source have a switch to enable bal output that was'nt engaged?

    Well he said it was working fine in passive mode, I wonder if that would have solved his problem?
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  • FTGV
    FTGV Posts: 3,649
    edited April 2012
    heiney9 wrote: »
    If they are missing the single ended inputs will not sound right.
    Actually their purpose appears merely short the inverted half of the input to ground avoiding the potential for extraneous noise pick up,sound should'nt change.
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