Adcom : thumbs up or down

[Charles Turner]

I still have my Adcom separates from the late 80s...the 555 series (GFA-555 amp, GFP-555 preamp, GFT-555 tuner) and they work great. When they first came out they received a lot of positive press from Stereophile et al...especially the preamp. The preamp was considered to be very "neutral" and I personally thought the phono section was quite good. The local Klipsch dealer carried the line and I recall they believed the series to be a strong performer, especially for the price. The only problem I ever had with the units were the front rocker power switches and apparently others had similiar problems.

I would agree they tend to be on the bright side and a bit bass heavy...at least with my Cornwalls. When I changed back to vinyl they were replaced by tubed components but my son still uses them and has never complained.

[dkbks]

My Adcom 535 amp has been powering Cornwalls for almost 15 years. Run almost every day. The 535, although the lowest power of the series - 60 watts per channel - was generally regarded as one of the best amps Adcom made. Its companion GTP-400 preamp/tuner is now relegated to phone stage work as a NAD A/V receiver is the pre-amp & powers the center & surrounds. The 400, however, was not totally trouble-free. The company went thru a lot of changes in the late 90's so I couldn't vouch for any of the later equipment. Adcom amps are generally regarded as good value for the money.

[v3spitfire]

I believe their stuff may did in the US is very good. A lot of their later preamps were made in Asia, and suffered from quality (sodder, connections). This seemed especially true with their early HT preamps. Their US made amps that were made in the US are tanks, sound great,(though maybe on the bright side for some). GFA535,45,55 etc are all US. My 7400 is as well (1999 or so), but I think sometime after (or during that model run) things got shifted overseas, where the trouble started. I've not heard the 5000 series. They did make an excellent straight line controller (passive device to use between source components and amp) if you want to completely bypass a pream.

[glr]

I have three (3)Adcom amps and have owned two (2) of them for over 5 years. I have been very pleased using them with KLF-30's and Forte II's.

My newest amp is a 5500 (200w per channel) and I've only had it for about a week. So far, so good. I've changed to a Rotel preamp/processor, the new 1068 and am getting used to it.

Anyone looking for a Adcom GTP-600 preamp and DDG-1 digital processor? I'm the original owner and they are in great shape.

As you can tell, I like Adcom equipment. Since they have been bought out, I'm not sure it's the same company. I've had problems getting a response from their customer service department (I was considering the new Adcom 860 II preamp).

[daveexplorer]

ok call me Crazy but I own (2) GFA-565 ,GFA-2535L, GFA-555II, GFA-5800, GFA-5300, GFA-5500, GFA-5400, GFA-5802, GFA-7807,GFA7607,

KM-4'S KM-6'S CHORUS, CHORUSII, (4)RS-35'S, RB-75'S, (2) RC-7'S, RF-7'S RB-81, RF-83, AND A thx ULTRA 2 SYSTEM. Just sold my T-5000's sad day

After playing with all combo's of amps and speakers I did not like The GFA-5400 or the GFA-5802 sounded harsh in the mid rang and high range.

OK now for the fun. Chorus series GFA-565 and the GFA-55II sound better to me than the other amps in Stereo. KM series sound Great with the GFA5800 and GFA,5300, ok so with the RF-7's i prfered the GFA-5800 although th e565's sounded good the bass seemed more boomy. the GFA5802 really seemed harsh I don't have alot of time on that amp and it may have not broken in yet. so the RB-75 ,RC-7 and the RS-35's I use with the GFA7807 paired with a GTP 880 it is a very good sounding combo sounds way better than when I had it hooked to a yamaha RX-V1700 receiver. Ok the THX ultra 2 system i use the GFA-7807 and it blows me away. although I can hear some white noise out of the amp wen there is a quiet scene with nothing playing. investigated and I hve 2 channels that had white noise same channels no matter what I did. Sent it back to ADCOM and they said the amp was within specs. and that it was because the speakers were efficient. So i took it apart and found that the 2 channels that were noisy shared the same transformer. There are 2 in that amp 1 powers 5 channels and the other 2 channels. so I was not happy with them on that. other than the white noise @ idle the amp is amazing. I currently using the GFA2535L to run the Chorus speakers in my Garage. this amp seems to be a liitl muttled @ high volumes but very pleasent @ moderate levels.

[jacksonbart]

You're crazy.

[PrestonTom]

ok call me Crazy but I own (2) GFA-565 ,GFA-2535L, GFA-555II, GFA-5800, GFA-5300, GFA-5500, GFA-5400, GFA-5802, GFA-7807,GFA7607,

KM-4'S KM-6'S CHORUS, CHORUSII, (4)RS-35'S, RB-75'S, (2) RC-7'S, RF-7'S RB-81, RF-83, AND A thx ULTRA 2 SYSTEM. Just sold my T-5000's sad day

After playing with all combo's of amps and speakers I did not like The GFA-5400 or the GFA-5802 sounded harsh in the mid rang and high range.

OK now for the fun. Chorus series GFA-565 and the GFA-55II sound better to me than the other amps in Stereo. KM series sound Great with the GFA5800 and GFA,5300, ok so with the RF-7's i prfered the GFA-5800 although th e565's sounded good the bass seemed more boomy. the GFA5802 really seemed harsh I don't have alot of time on that amp and it may have not broken in yet. so the RB-75 ,RC-7 and the RS-35's I use with the GFA7807 paired with a GTP 880 it is a very good sounding combo sounds way better than when I had it hooked to a yamaha RX-V1700 receiver. Ok the THX ultra 2 system i use the GFA-7807 and it blows me away. although I can hear some white noise out of the amp wen there is a quiet scene with nothing playing. investigated and I hve 2 channels that had white noise same channels no matter what I did. Sent it back to ADCOM and they said the amp was within specs. and that it was because the speakers were efficient. So i took it apart and found that the 2 channels that were noisy shared the same transformer. There are 2 in that amp 1 powers 5 channels and the other 2 channels. so I was not happy with them on that. other than the white noise @ idle the amp is amazing. I currently using the GFA2535L to run the Chorus speakers in my Garage. this amp seems to be a liitl muttled @ high volumes but very pleasent @ moderate levels.

Well, not all Adcom amps are the same, some were initially designed by Nelson Pass and they can sound quite good. You mentioned the GFA 585. That is a very nice amp but hard to find (it was a limited edition). I have the Nelso Pass designed- GFA 555 & 545s (series ii). I like them, but there is an easy way to improve them.

Some, but not all of the series ii, have bypass caps on the power supply caps. I would encourage folks with the GFA 555 to try that as a mod. Simply parallel a 22 or a 47 uF cap accross each of the big caps. The bass will become very "solid". It is simple and reversible (in case you prefer a sloppier bass). The cap does not need to be fancy. Simply get a crossover cap, so you won't get confused about the polarity (the big PS caps are polar electrolytics and the "crossover" electrolytics are non-polar). I used Bennic and it cost me a few dollars and an hour (I checked the bias while I had it opened up). Very good bang for the buck. Search the forums over at DIYaudio, DJK has mentioned this mod.

For the life of me I do not understand why this mod works, since the diiference in capacitance is trivial. You will not see a difference on the scope. It probably means that the effect (deficit) is not steady-state. The difference is most audible on the low frequency percussives.

Good Luck,

-Tom

[Jmartin]

I may be interested in the GTP-600. What are you asking for it? Does everything work all the time?

[kohill]

I had a 545 that powered my RF-7's for a couple of years. It always did a nice job. Plenty of power and

nice sound especially on movies and rock. Not as smooth as the Mcintosh that replaced it. It did not hold it's

value as well as I would have liked. Overall a good amp.

[MD1032]

Chris (noki139), who I bought my fortes from here on the forums, had an Adcom amp and the Fortes just sounded amazing with it. The biggest thing that I noticed was that the soundstage was GIGANTIC with the Adcom amp. It was just amazing. I kept turning around thinking sounds were behind me... good stuff!!

[Fish]

I've been thinkin about this for a few years now,thumbs sideways.

[bigdaddy]

I have an adcom GFA-1a from the 70s and I love it. I must admit I don't have a lot of experience with different amps. I always have just used my receiver. It drives my Fortes very nicely. I haven't hooked the Forte IIs to it yet.

[jdm56]

Adcom was recently taken over by Emerson. I hope the brand gets back on it's feet.

I've got a GFA-5500 I use in my two channel system. I bought it used on Ebay for $500 bucks. It looks brand new and performs like a champ. It sounds great with my power-hog Mo-Fi's. I also have a "factory refurbished" GTP-602 tuner/preamp I use in the same system. It has been stone reliable for me, and seems very quiet and neutral. It has remote tone controls which I really love (I guess I'm no purist).

So I guess on the basis of my experience with the brand, I'd have to give Adcom two big thumbs up.[Y][Y]

[jacksonbart]

Does anyone know anything about the brand "adcom". Iwas recently given an amp/preamp that is about 12 years old. I plan on using it for 2 channel stereo. I have it hooked up to my RF3's now and it is simply explosive. Does anyone know anything about the brand adcom?????? Im kinda new at this....

Dang!!! That Amp is now 16 years old. I lost both thumbs in the war.

[rroobbcc]

ok call me Crazy but I own (2) GFA-565 ,GFA-2535L, GFA-555II, GFA-5800, GFA-5300, GFA-5500, GFA-5400, GFA-5802, GFA-7807,GFA7607,

KM-4'S KM-6'S CHORUS, CHORUSII, (4)RS-35'S, RB-75'S, (2) RC-7'S, RF-7'S RB-81, RF-83, AND A thx ULTRA 2 SYSTEM. Just sold my T-5000's sad day

After playing with all combo's of amps and speakers I did not like The GFA-5400 or the GFA-5802 sounded harsh in the mid rang and high range.

OK now for the fun. Chorus series GFA-565 and the GFA-55II sound better to me than the other amps in Stereo. KM series sound Great with the GFA5800 and GFA,5300, ok so with the RF-7's i prfered the GFA-5800 although th e565's sounded good the bass seemed more boomy. the GFA5802 really seemed harsh I don't have alot of time on that amp and it may have not broken in yet. so the RB-75 ,RC-7 and the RS-35's I use with the GFA7807 paired with a GTP 880 it is a very good sounding combo sounds way better than when I had it hooked to a yamaha RX-V1700 receiver. Ok the THX ultra 2 system i use the GFA-7807 and it blows me away. although I can hear some white noise out of the amp wen there is a quiet scene with nothing playing. investigated and I hve 2 channels that had white noise same channels no matter what I did. Sent it back to ADCOM and they said the amp was within specs. and that it was because the speakers were efficient. So i took it apart and found that the 2 channels that were noisy shared the same transformer. There are 2 in that amp 1 powers 5 channels and the other 2 channels. so I was not happy with them on that. other than the white noise @ idle the amp is amazing. I currently using the GFA2535L to run the Chorus speakers in my Garage. this amp seems to be a liitl muttled @ high volumes but very pleasent @ moderate levels.

I don't think you are crazy. I own a GFA-5802, GFA-555, GFA-555II, two GFA-545II, GFP-555, GTP-500II, GDA-600, GCD-575, and GCD-750. I think Adcom offers a really good price/performance value.

Regarding the GFA-5802, I encourage you to give it an hour to warm-up before doing any critical listening. This was the first piece of equipment that convinced that some gear is in fact better when warm. I use my GFA-5802 to power my big Infinity RS 9 Kappas, but have not yet listened to it driving the Forte IIs. However, judging from time listening on the 9 Kappas, I would say that when warm the GFA-5802 has a smoother top end than both the GFA-555II and the GFA-555. The harshest of these three is the GFA-555, but it is also the amp with the most bass "slam". I also want to add that I never picked up on the different cold vs. warm performance of the GFA-5802 until I updated my source gear from an old Carver TL-3220 (which turns out was VERY harsh) to eventually an Adcom GCD-750 CD player. Once I removed the Carver and eliminated my "garbage in/garbage out" issue, it became clear that the GFA-5802 was a different amp once warm. I have read a number of user reviews which criticize the GFA-5802 as being harsh, and my experience leaves me asking two questions... what was the source gear and preamp? did they let the amp warm up first?

[rroobbcc]

Adcom was recently taken over by Emerson. I hope the brand gets back on it's feet.

Adcom was not taken over by Emerson. Adcom and Emerson formed a joint venture which is a compant named "Advanced Sound and Image" or ASI. Emerson's main contribution was cash (much of which was routed through to Adcom), and Adcom's main contribution was intellectual property. So basically Adcom sold rights to its IP to a new company that it owns a minority stake in.

Now eventually this may lead to a complete acquisition of Adcom by Emerson, however by forming a joint venture both parties have the opportunity to test whether their relationship and business assumptions that would support such an acquisition are in fact valid.

[jdm56]

Adcom was recently taken over by Emerson. I hope the brand gets back on it's feet.

Adcom was not taken over by Emerson. Adcom and Emerson formed a joint venture which is a compant named "Advanced Sound and Image" or ASI. Emerson's main contribution was cash (much of which was routed through to Adcom), and Adcom's main contribution was intellectual property. So basically Adcom sold rights to its IP to a new company that it owns a minority stake in.

Now eventually this may lead to a complete acquisition of Adcom by Emerson, however by forming a joint venture both parties have the opportunity to test whether their relationship and business assumptions that would support such an acquisition are in fact valid.

Well, yeah...that's what I meant to say.[:S]