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View Full Version : Albarry M-408 repair and mods



pulsestudio
13-02-2009, 19:35
Hi I am looking for a pair of Albarry M-408 or M-1008 mono blocks, I am not bothered if they are duff and in need of some internal attention provided the cosmetics are in very good to excellent condition, and have the Red Perspex front panels, cash waiting and I can collect within a reasonable distance from Oxford.
PM me if you have any please.
cheers
Paul

pulsestudio
14-02-2009, 10:29
Hi Ian

I have recieved your PM, many thanks, tried to respond but your "inbox" is full.

cheers
Paul

pulsestudio
10-03-2009, 17:36
I have now had a member of a fishy forum contact me and this weekend I will be the proud owner of a pair of Albarry M-408 mono blocks, sadly one of them has died but the cosmetic condition is virtually mint, so a repair will be quickly administered by myself and then I will have the full Albarry compliment, DMP1 pre-amp, APS1 pre power supply and 2x M-408 mono blocks, I can't wait to get them all wired up and singing, I will post some pics when this happens, very 80's retro with lovely red perspex front panels. thanks to anyone who mailed with info, this thread is now :closed:

Mike
10-03-2009, 19:14
Good show!

We await piccy's with anticipation. :)

Gromit
10-03-2009, 23:32
Oooh nice. :)

I remember hearing these many years ago at the Swiss Cottage hifi show - L-07D turntable with the Alberry amps into a pair of those huge Allison corner-situ'd speakers. Laavely. :)

pulsestudio
10-03-2009, 23:46
I don't believe this last post :scratch:
Richard I was at the Swiss Cottage Audio Show back in the late 80's, possibly '87, Albarry had a room of their own and these amps were playing and stole the show for me, somehow they stayed with me all these years and for the past couple of years I have been hankering after the complete set-up, I just remember that the sound just grabbed you by the balls and I couldn't leave the room, and the red glow from the front panels gave them the look and feel of valve amps.
My search is now over and I can't wait to see/hear if my memory has been playing tricks with my mind, they have a huge cult following in Italy and there are some dedicated affectionardos here in the UK that swear by them, I hope that I will not be dissapointed after all this time, thanks for the post Richard, and memories of a great Hi-Fi experience.
Paul

Dandy
15-03-2009, 00:07
Well done Paul, glad you got a pair. I'd be really interested to hear what you think of them.
Dave

pulsestudio
15-03-2009, 13:32
Hi Dave

Yep finally have the little Red beasts, picked them up yesterday from a fellow PFM'er from Bristol, one is in need of a repair but at least I have the other to use for reference to help the repair as no circuit is available for the M-408's.

Actually Dave you could possibly answer a very simple question for me, when you power them up are both lights on the front panel lit all the time or only the power LED light, one of mine has the protection LED out, but not too sure whether this is the faulty one or not.

While I am here does anyone have any info on these amps by way of schematics, board layout, or just general info, I know their heritage so do not need to know their history etc, but any help with circuits or layout would be most welcome, if not then it is a long and arduous task of reverse engineering them from scratch, arghhhhhhhh !!!!
Paul

DSJR
15-03-2009, 14:01
I think there was DC on the output of the faulty one, so don't go connecting up your vintage BBC speakers to them..

As I remember, only one light illuminated when they were running......

tubehunter
15-03-2009, 16:30
Hi
I have some diagrams of these amps, might help.
They have a badly designed protection circuit which you can remove.

http://i514.photobucket.com/albums/t350/halx00/Albarry_sch1.gif

http://i514.photobucket.com/albums/t350/halx00/Albarry_sch3.gif

http://i514.photobucket.com/albums/t350/halx00/Albarry_prot1.gif

http://i514.photobucket.com/albums/t350/halx00/photo1a.jpg

Duncan

pulsestudio
15-03-2009, 21:34
Hi Duncan, thanks for the info but I have already seen these circuits on the Italian site, the M-408 is a completely different ball game, and quite different to the M-1008 unfortunately, but I appreciate your help and time. I have been working on the duff M-408 for the best part of the day and I believe that I have now found the problem, there are 2x 0.22 ohm 4 Watt Welwyn resistors gone open circuit, one is fried, both output transistors TIP146 and TIP147 are reading around 1 ohm between collector and emmiter junction and the 2SC546 that senses the temperature of the output devices was totally cooked, all this adds up to a very sad amp, I have most of the parts so a rebuild will be underway when I get the Welwyn resistors from Farnell, I think I will eventually remove the protection circuit as a good colleague of mine has suggested that it does not really need it provided I don't try to run it into a couple of ohm load, so the day draws near for the final push to hear these birds sing again.
Thanks again Duncan for your offer of help, truly appreciated ;)

Paul

Dandy
17-03-2009, 13:54
Hi Paul,

Only the "power" LED in the middle should be lit. The "protection" LED will only be lit when something has gone wrong e.g. shorted output.

Dave

DSJR
17-03-2009, 14:14
When you have the amps dismantled Paul, any chance of some pics to go with the others here, so we can all see the differences in their layout?

pulsestudio
17-03-2009, 15:42
When you have the amps dismantled Paul, any chance of some pics to go with the others here, so we can all see the differences in their layout?

Hi Dave ( Dandy ), thanks so much mate, that has confirmed my thoughts 100%, many thanks.

Hi David so you want to see my poor old Albarry innards?? these are the M-408 mono blocks as you know David, I fully intend to reverse engineer the complete circuit for all to see at some stage, and finally get some form of technical history for these old retro classics, but first I must get the broken one un-broken, I have all the parts to afford the repair now so maybe tonight if I feel in the mood to do the swap out.
I will post some pics of the innards of the M-408 mono block and DMP1 pre-amp in a bit, need to upload them to photobucket ;)
paul

pulsestudio
17-03-2009, 15:51
Albarry M-408 Series II mono bocks internals:

http://i202.photobucket.com/albums/aa59/pulsestudio/Knobs/STA60006.jpg

http://i202.photobucket.com/albums/aa59/pulsestudio/Knobs/STA60003.jpg

http://i202.photobucket.com/albums/aa59/pulsestudio/Knobs/STA60002.jpg

Albarry DMP1 will be posted later

Paul

pulsestudio
17-03-2009, 16:04
Albarry DMP1 Pre-amp innards:

Original look of the pre-amp and power regulator boards:

http://i202.photobucket.com/albums/aa59/pulsestudio/Knobs/Albarry%20M-408/STA60013.jpg

http://i202.photobucket.com/albums/aa59/pulsestudio/Knobs/Albarry%20M-408/STA60014.jpg

Now remove these horrible things: and replace with Panasonic FC for the large 4700uF and Panasonic NHG's for all the others.

http://i202.photobucket.com/albums/aa59/pulsestudio/Knobs/Albarry%20M-408/STA60048.jpg

And leave it looking like this:

http://i202.photobucket.com/albums/aa59/pulsestudio/Knobs/Albarry%20M-408/STA60045.jpg

http://i202.photobucket.com/albums/aa59/pulsestudio/Knobs/Albarry%20M-408/STA60039.jpg

That's it, I will post the circuit when it has been done, and that will be a few weeks away yet.
Paul

pulsestudio
20-04-2009, 22:10
You may remeber that I have been searching for a pair of the Albarry M-408 mono blocks for some time, well I eventually got a pair albeit one was smoked, so a repair was needed to get them singing as a pair again, so I set about the repair and a total upgrade for these old 80's classics, and this is whhat they look like now that both amps have undergone surgery.

http://i202.photobucket.com/albums/aa59/pulsestudio/Albarry%20M-408%20amps/STA600141.jpg

http://i202.photobucket.com/albums/aa59/pulsestudio/Albarry%20M-408%20amps/STA600145.jpg

Doncha love em !! well OK maybe not, but for me they represent an era in the 80's that was all a little too, well brilliant in the world of hi-fi.
It has been an uphill struggle to get them this far, I have re-capped the 2x M-408 mono Blocks and the DMP1 pre-amp, the smoked mono block had both output transistors and the thermal compensation transistor cooked, repaired, re-capped, rewired and generally cleaned that one up and set up the bias and then the other one smoked, they had been in a damp storage unit for some time before I recieved them, so after a few weeks of slogging over a hot Weller they are both now up and singing. I am not going to offer my verdict yet as it is early doors, and I have to re-arrange my lounge set-up a bit, so a full review in a couple of weeks, hopefully!! that is if they survive long enough ;)
Paul

Spectral Morn
20-04-2009, 23:20
Nice job.

I remember Albarry as the shop I worked in as a Saturday boy used to do them...but stopped for some reason. I can't remember what they sounded like at all...I can't even remember if I ever heard them....but I saw them. I love the look of them...simple understated and classy. Love the red acrylic.

Very nice photos too.


Regards D S D L

pulsestudio
24-04-2009, 11:45
:steam: :scratch:

Yes you may have guessed !! the M-408 that was originally dead, has now phizzed, crackled, burning smell and smoked again, this all happeded the other night :( I simply powered up the pre-amp followed by the M-408 mono blocks and bang :o I am totally gutted after spending a month getting everything rebuilt and re-capped simply for this to happen on power up.

I have removed the offending 408 amp board and again the 2x output devices are an almost dead short across the collecter/emitter junction as too is the thermal auto bias transistor, I am now debating whether to replace the Albarry designed/built amp boards with a pair of Avondale NCC200 amp boards in both of the M-408 mono blocks. I have built many NCC200 amps and they are superb, and they don't smoke being a very stable deriative of the original RCA design as used in many Naim amps, I really would have liked to get the Albarry amps running just to have something that was typical of the 80's era but with the almost unpredictable reliability factor of these amps in question, is it worth it ??

I would love to hear from anyone out there that has a pair of Albarry M408's in good running order that may be prepared to offer me some help with the bias setting as I feel that this may not have been set correctly by me, I did set it to 5mV across the 0.22 ohm emitter resistor which would yeild a bias current of around 20mA, does anyone know if this is correct?? could you possibly check it on your M-408's and advise me what they are reading, or even loan me a single M-408 to carry out some tests on, just so that I have the correct voltage/current set-up on my amps, anyone to my rescue please, I am more than prepared to pay for any time and expences incurred as a result of any info provided, so please can anyone help here?
many thanks
Paul

DSJR
24-04-2009, 17:14
What on Earth happened to the chap who designed (?) and built them? I hope he's still around, but possibly someone may be able to contact him. I did check with HiFi Dave but he couldn't help (and is away for a short while now).

Good luck Paul......

pulsestudio
24-04-2009, 21:34
Cheers Dave but I think I have now conceded to the Albarry amp boards, I have placed an order with Les for my fourth pair of NCC200 boards and have all the components in stock now to put a pair together, at least I know the Avondale amps are solid as a rock and sound simply divine, so I think I will proceed with plan B. My intention now is to remove the Albarry boards and repair the smoked one and then build them into a test bench supply and work on them on the bench fully loaded, I will then put them to one side just in case I ever decide to sell the Albarry amps as stock, but that is very, very unlikely now, more to do and other projects have now been placed on hold, I still have my Thinn ongoing, a NAP250 to repair/service, a TT speed controller to prototype and finally a pair of speakers to test a theory of mine on, no not the Export Monitors, 3/5a's with a Kef T15 and Coles 4001G, I built the x-over about a year ago and still waiting to put it into place, does this DIY Hi-Fi ever end :)

Paul

pulsestudio
26-04-2009, 18:33
Well done Paul, glad you got a pair. I'd be really interested to hear what you think of them.
Dave

Hi Dave

I have sent a PM to you in the hope that you may be able to help mate ;)
Let me know if this is possible please.
cheers

Paul

Dandy
29-01-2010, 09:27
Hi Paul,
Sorry, only just logged in to get your PM! I've sent you a response, give me a call if not sorted yet.
Dave

exiakiaz
19-08-2011, 19:06
Hi Duncan,
Tried to access your wiring diagrams on photobucket but unfortunately they have been removed. I wonder if you would be kind enough to email me a copy,
it would be greatly appreciated.
Also, do you have any idea of how to deactivate the protection circuit on these
units ?

Many thanks,

Kind regards,
Chris.

exiakiaz
19-08-2011, 19:14
Hi there,
Do you by any chance have wiring diagrams for the Albarry 408's Or any info at all ?

I have had mine for over 30 years, but now one has developed a fault.

Any assistance would be greatly appreciated.
Kind regards,
Chris.

DSJR
19-08-2011, 19:22
Why not ask Neil himself, since he's alive, well and making Albarry's again?