Adcom GFA-5400

heiney9

MKZ wrote: »

That's very possible.
Update: I used my wife's out of state cell phone to call him and he just picked up. He was surprised it was me. I told him one of the channel is not working and want to give back since he was promised me that I can return it if there is anything wrong. He told me there is 8 fuses inside and take a look if it is still not working call him back and hang up. I think he's bs. Is it possible to check? I don't know where are those and how to get it change. Please take a look inside here.

Do you know where I can get the service manual you mentioned?

Yes you can check those. I doubt there are 8 in there but since I haven't looked in a 5400 it's possible. Externally there is an AC fuse if that was blown you'd have no output or power for that matter.

Internally there should be power supply rail fuses. Older Adcoms had (2) for each channel. The 5400 may have more not sure. Visually inspect and also pull the fuses and test with a meter (if you have one).

WARNING: MAKE SURE THE POWER IS OFF AND THE CHORD IS DISCONNECTED and MAKE SURE THE AMP HASN"T BEEN ON FOR 30 minutes so the caps are completely drained before trying this.

A bad fuse normally won't cause a hum. It's either working or it's blown.

H9

DarqueKnight

The service manual is available from Adcom. They cost around $25.

The service manual shows six fuses:

1. F001-8A, 250V Power Cord Fuse. Adcom part number 19000800.
2. F701-1A, 250V Protection Circuit Power Supply Fuse. Adcom part number 19000100.
3. F601-5A, 250V Left Channel Amplifer Printed Circuit Board Fuse. Adcom part number 19000500.
4. F602-5A, 250V Right Channel Amplifer Printed Circuit Board Fuse. Adcom part number 19000500.
5. F603-5A, 250V Left Channel Amplifer Printed Circuit Board Fuse. Adcom part number 19000500.
6. F604-5A, 250V Right ChannelAmplifer Printed Circuit Board Fuse. Adcom part number 19000500.

Since the problem is only occuring in the right channel, fuses F602 and F604 are the ones you want to check. These fuses would be located on the circuit board that is attached to the right heat sink (as you are standing facing the front of the amp). If these fuses are good, then you might have one or more bad bad power transistors. In that case, I advise returning the amp for a refund.

The manual does not specify that special type fuses are used, but I would call Adcom and ask if any 5A., 250V fuse would work.

ViperZ

That's weird, my schematic calls for 2 6.5A fuses on each channel, not 5A.

DarqueKnight

That's not weird at all. Manufacturers change parts all the time. My service manual has has the schematics for both the ver.1 and ver.2 GFA-5400. Both schematics have the 5A rail fuses.

The ver.1 schematic is dated July 23, 1999. The ver.2 schematic is dated July 22, 1999.

MKZ

I'll check the fuse when I got home, thank you all for the helpful information.
I did email to Adcom to order the service manual and here is the reply:

---

Hello,

The GFA-5400 service information is not available, as it is a current
product. It may only be serviced by an Authorized Adcom Service center.

Should you desire to pursue repairing this product, I suggest you
contact the nearest Adcom Authorized Service Center and take or ship
your unit to them. For your reference, Adcom does not repair legacy
products in-house. You can find the Adcom authorized service center
nearest you here:
http://www.adcom.com/dealer_locator.aspx?action=service


Best Regards,

Stan Brown
Adcom Sales Engineer


ADCOM LLC
8541 E. Anderson Dr.
Suite 101
Scottsdale, AZ 85255
Direct: 480-889-3112
Company: 480-607-2277
Cell: 480-907-9336
FAX: 480-348-9876
Email: sbrown@adcom.com

DarqueKnight

Wow, Adcom has changed a lot since being purchased in 2002 by Klein Technology Group. During the good old days, I was able to purchase service manuals for all my Adcom gear. In addition to that, I have emailed and called Adcom engineers to discuss modifications to improve performance. They were always very upfront and enthusiastic about discussing where corners were cut to meet a price point and offering suggestions to improve performance.

OK, since the new Adcom is being an **** about this, you may be able to acquire a service manual from this company:www.servicemanuals.net

Adcom is not one of the brands they normally stock service manuals for. You can go to the link above and ask them to search for one. Good luck.

ka7niq

CAN I try my Adcom 585 on the SRS 2's Darqeknight ?
Dont wanna blow the RDO 194's !

DarqueKnight

If you are asking if the GFA-585 is a common ground design, the answer is I don't know. I have no familiarity with the 585 other than knowing it is one of their rare, limited edition designs. A simple continuity check between the negative terminals of both channels should suffice. If it is not common ground, strapping the negative terminals together should work, as it does with their other non-common ground amps. However, I'd check with Adcom to be sure.

heiney9

DarqueKnight wrote: »

If you are asking if the GFA-585 is a common ground design, the answer is I don't know. I have no familiarity with the 585 other than knowing it is one of their rare, limited edition designs. A simple continuity check between the negative terminals of both channels should suffice. If it is not common ground, strapping the negative terminals together should work, as it does with their other non-common ground amps. However, I'd check with Adcom to be sure.

This is your best course of action. I believe this was discussed with Ben6270 at one point because he has SDA's and a GFA 585. I tried to find the thread but I couldn't find the specific thread.

A continuity check is always possible to determine common ground, but as I stated and Darqueknight stated as well, contact Adcom to see if the neg. terminals can be strapped. I know they can be on the GFA 565's which the 585 is the same thing in a single chassis. I just can't remember for certain and I don't want to be responsible for breaking your equipment.

H9

ka7niq

heiney9 wrote: »

This is your best course of action. I believe this was discussed with Ben6270 at one point because he has SDA's and a GFA 585. I tried to find the thread but I couldn't find the specific thread.

A continuity check is always possible to determine common ground, but as I stated and Darqueknight stated as well, contact Adcom to see if the neg. terminals can be strapped. I know they can be on the GFA 565's which the 585 is the same thing in a single chassis. I just can't remember for certain and I don't want to be responsible for breaking your equipment.

H9

HERE is an old thread H9 http://www.polkaudio.com/forums/archive/index.php/t-46864.html

I see Ben had the same problem that plagues these amps, IF not caught in time.
Mine came with this problem.
FORTUNATELY, my best friend is a full time amp tech, and high end audiophile.
He builds his own stuff, and has KEF Reference speakers.
He saw the cap leaking on the board, and replaced it, and SAVED the board.
The boars go, and amp is shot, there are no more replacements.

He also replaced the driver transistors that went out when the cap leaked.
Matched em too!

My 585 runs pretty warm, but holds bias.
Fan comes on when ya lean into it.

It is an excellent amp, it really is.

But SO is my Moscode 600 and the Luxman M 117 ....

I never get bored

heiney9

ka7niq wrote: »

HERE is an old thread H9 http://www.polkaudio.com/forums/archive/index.php/t-46864.html

I see Ben had the same problem that plagues these amps, IF not caught in time.
Mine came with this problem.
FORTUNATELY, my best friend is a full time amp tech, and high end audiophile.
He builds his own stuff, and has KEF Reference speakers.
He saw the cap leaking on the board, and replaced it, and SAVED the board.
The boars go, and amp is shot, there are no more replacements.

He also replaced the driver transistors that went out when the cap leaked.
Matched em too!

My 585 runs pretty warm, but holds bias.
Fan comes on when ya lean into it.

It is an excellent amp, it really is.

But SO is my Moscode 600 and the Luxman M 117 ....

I never get bored

Not all had that problem but a good number of them did. My brother has a 585 and so far no leaking problem. The 565's had this same issue as the caps were sourced from the same vendor at during the same time frame.

Biggest problem is the boards are no longer and haven't been available for a long time. If caught early they can be cleaned like new even though it's a PITA.

H9

heiney9

ka7niq wrote:

My 585 runs pretty warm, but holds bias.
Fan comes on when ya lean into it.

It is an excellent amp, it really is.

But SO is my Moscode 600 and the Luxman M 117 ....

I never get bored

The fan is a factory installed option as they didn't come this way unless ordered during production or the fan assembly could be bought seperately. My brother sold his (fan) on e-bay many years ago and got a prettyy good chunk of change for it, they are quite rare by themselves.

H9

ka7niq

Yeah H9, mine has the fan, and has been all gone through by my friend.
We left it stock, cause I wanted to see what it was all about in it's stock form first.

It is an excellent amp, different then my Luxman M 117.
I would call it a neutral amp with little "personality" of it;s own.
The Luxman M 117 was designed to sound like a tube amp, w/o the Carver tricks.
The Luxman has a definite "sound" to it, and imposes it's "personality" on all that runs through it.
NICE for horns and bright speakers.

The Adcom 585 will not hide bad **** in front of it, nor will it "tame" a bright speaker.
But if all is right, it can sound really good.

I agree with a lot of what has been said in this thread, Adcom gets a bad rap sometimes.'
I think they offer excellet value for money, generally.

heiney9

ka7niq wrote: »

Yeah H9, mine has the fan, and has been all gone through by my friend.
We left it stock, cause I wanted to see what it was all about in it's stock form first.

It is an excellent amp, different then my Luxman M 117.
I would call it a neutral amp with little "personality" of it;s own.
The Luxman M 117 was designed to sound like a tube amp, w/o the Carver tricks.
The Luxman has a definite "sound" to it, and imposes it's "personality" on all that runs through it.
NICE for horns and bright speakers.

The Adcom 585 will not hide bad **** in front of it, nor will it "tame" a bright speaker.
But if all is right, it can sound really good.

I agree with a lot of what has been said in this thread, Adcom gets a bad rap sometimes.'
I think they offer excellet value for money, generally.

I have to agree, everyone knows I'm a bit of an Adcom fan. I just ahve yet to find anything in it's price range or for that fact more that isn't a lateral move. My next amp I'm shooting for a level or 2 higher. I've never considered my Adcom to be bright.

I have a nifty little Adcom piece only sold overseas and in Canada when new in 1997. It's a GCA-510 integrated or control amp which Adcom calls it. It is essentially a GFA-535 (sans the dual I/C transformers) w/ a single high power Torrid and (4) Bi-polar output transistors per channel.

It's a very high gain, high bias amplifier with a passive line controller. There is no pre-amp stage. It's like having the SLC 505 passive pre and a GFA 535 amp all in one. This thing sounds fantastic. Rated at 50wpc/8 and 75 wpc/4. It has all the bottom end and control you could want and the jighs are crystal clear. The amazing thing to me is when I put my ear up to the speakers in my office rig it is dead silent, no hiss at all. It also seems to play well beyind it's rated output. It runs very hot because the amp is set for high gain to have enough oomph since there is no pre-amp section.

Anyway I have always been impressed with the initial Adcom offerings in the mid/late 80's. Nelson Pass, Victor Campos, Walt Yung were all involved early on and I still feel those early Adcom pieces were the best.

The GFA 5802 and GFP-750 are stellar pieces as well. It's all good but those first pieces were special at the time and hold their own today w/o any trouble.

I still have my trusty 545 which I bought new in 1986 and never a hiccup.

H9