Copland CSA 14, rework and upgrade.

Hi Everyone,

been a while since i have posted on here, my apologies, but life has been abit busy recently.

The main reason I am here is to get thoughts from members on upgrading my beloved Copland amp. its coming on for 20years old now, and while built like a battleship one or two things have begen to crop up.
namely one channel has began to cut out, if i have the amp switched off for a period of time.(therefore i leave it on), and dreaded 'crackling' has began to affect the volume switch, a failing alps potentiometer i suspect, i think this also effects the channel balance, but i dont use that in any case.

Anyway, i was wondering if its maybe a case of having a look and simply rectifying these faults with new componets, or a more indepth look at what i have and upgrading aspects at the same time, with new capacitors, regulators, etc. as i am fairly electraiclly minded, ie i test and rebuild ECU's all day, I think I could perform said upgrades well.

Would welcome any thoughts and suggestions on the matter, meanwhile here are a few pics of my innerards!

http://i620.photobucket.com/albums/t...1/SAM_0066.jpg

http://i620.photobucket.com/albums/t...1/SAM_0067.jpg

Hi Liam,

I have a 1995 CSA14, I had a problem with the left channel over heating and eventually causing the cutout circuit to switch the amp off completely, this was traced to the valve in the left channel, now running NOS mullards and all my problems have gone.

Nice amp isn't it :)

Steve

Hi Steve

Thanks for the tip btw, havent really had any cutout issues, feel its more consistant with a dry joint or failing component, as channel is intermittant when cold.
Have noticed that two of the big caps are bulging ever so slightly at the top, so i will be replacing them in due course.

Lovelly sounding amp though, particulary with female voices, just started to take it apart today, so am getting my magnifying glass out tomorrow after work to have a good look at the pcb.

Might 63V caps last even longer, or will this upset things?

voltage doesnt really matter as long as its greater than the 50v thats currently present.

just taken out all the caps, awaiting replacements atm

Caps and valves will be a good start. let it run a few weeks then maybe think about the rectifiers, they aren't Schotky devices. Take a look at the volume pot, maybe a new one or a stepped attenuator of similar range and value.

You really need to understand the circuit be fore doing anything beyond that, otherwise it's just pure guesswork. Best of luck with it.

Hi Simon

am only going to recap and replace the potentiometers in any case, may have a look at the rectifiers later, as u suggested. The vales are new (old stock)siemens items, so they are fine, they just lost the markings when the pins were cleaned thats all.

Any advice/recommendations when it comes to caps, and rectifiers? going maybe mundorf, not keen on alps though, stepped attenuators i may look into, any concerns over precise volume contol?

So finally got round to recapping the copland, took a while as i havent had much time to get round to it recently.

It also gave me the oppourtunity to strip it down fully, have a look at the build quality and give it a clean and dust up.

starting to strip it down, just making a note of what goes where, such as these power cables from the toroidal transformer.

http://img16.imageshack.us/img16/6585/sam0315hi.jpg

alps potentiometers on the volume, and the balance.

http://img534.imageshack.us/img534/7855/sam0318m.jpg

electrolytics were joe masters, which i havent really come across before, so its difficult to know how to rate them.
most electrolytics removed from the board, just a few at the bottom in order to not confuse myself, i replaced them in due course.
http://img199.imageshack.us/img199/3168/sam0320u.jpg
By rabid1981 at 2011-09-26

where the main powercaps sit.

http://img171.imageshack.us/img171/5056/sam0321d.jpg
By rabid1981 at 2011-09-26

some nice big mundorf 10000uf 63volts instead.

http://img545.imageshack.us/img545/1922/sam0323c.jpg
By rabid1981 at 2011-09-26

bare chassis, bar the transformer, and leads. Didnt replace them, just the brass ends due to oxidization.

http://img194.imageshack.us/img194/5994/sam0324e.jpg
By rabid1981 at 2011-09-26

front plate back on.

http://img197.imageshack.us/img197/9683/sam0325t.jpg
By rabid1981 at 2011-09-26

almost all done now, replacements were a little bigger than stock so where they were touching in just two cases, i glued a tiny peice of foam between them.

http://img827.imageshack.us/img827/6715/sam0328pa.jpg
By rabid1981 at 2011-09-26

all back together and warming up!

http://img84.imageshack.us/img84/4277/sam0330a.jpg
By rabid1981 at 2011-09-26

nice night shot, turned it on, thankfully no hum or burning! lol

http://img813.imageshack.us/img813/5762/sam0333u.jpg
By rabid1981 at 2011-09-26

additioanlly the speakers hookups were replaced with HGC pure silver wire.
the remaining caps were all fairly decent ELNA, NKZ, and Nichicon

big difference, more than i anticipated if i am honest, seems theres more drive than before and detail too, hasnt really resolved the limited soundstage, but cant hope for everything. overall i would recommend giving it a whirl, especailly on amps coming upto 20 years old, like mine.
only cost 150 in parts so much cheaper than a new amp.

what say you? also have a Technics SL 10 refinish, if anyone is interested for me to post..

Nice job Liam.
Did you just do the caps?

Always nice when nothing goes pop after these rebuilds.
I've got an Exposure Pre and Power waiting for similar attention.

just the caps, may look at the rectifiyers at a later date.

yeap, its always a relief! just totting up my copland cda266 for a recap and clock upgrade atm

The 266 was a pretty good machine in stock form, so not sure if the clock would "need" upgrading, since the importance of the latter was quite well understood by this time. have a look at the line output stage to see if a careful recap could warm the tone up a little?

The CSA14 pots look like Alps Black Beauties, which were well thought of weren't they - supposedly better than the standard "blue" version?

SL10 re-do? YES PLEASE!!!!!! :lol:

Thanks for the tip dave, i am not sure what alps model, as i didnt remove them from the pcb for a closer look, they did crackle a little but some contact cleaner sorted it out, so didnt mess with them in the end.

as for the cda 266, i will have a look at the output and power supply boards for a recap, u can see some 0.15uf caps right there, cant make out a name, the rest are phillips items, clcok is in the bottom left corner.

http://img600.imageshack.us/img600/2193/sam0061fg.jpg
By rabid1981 at 2011-09-27

Quote:

---

Originally Posted by Rabid1981

just the caps, may look at the rectifiyers at a later date.

yeap, its always a relief! just totting up my copland cda266 for a recap and clock upgrade atm

---

Hi all.
I am another CSA14 user. At the moment it is on my workbench, having had most of the caps replaced....nearly finished....but I want to replace the bridge rectifiers too.
There are 5 of them.
These are the specs:
D5,D6, D105: All 3 are square plastic encapsulations with 4 legs, 10amp 400v according to the manual
D7 & D8 are similar slightly smaller 3amp 400v devices. Any suggestions as to whether schottky diodes are suitable replacement upgrades and as to how to connect them?
I can follow instructions but I'm not an electronics engineer!

Any takers for this one please?

Quote:

---

Originally Posted by vintageaxeman

Hi all.
I am another CSA14 user. At the moment it is on my workbench, having had most of the caps replaced....nearly finished....but I want to replace the bridge rectifiers too.
There are 5 of them.
These are the specs:
D5,D6, D105: All 3 are square plastic encapsulations with 4 legs, 10amp 400v according to the manual
D7 & D8 are similar slightly smaller 3amp 400v devices. Any suggestions as to whether schottky diodes are suitable replacement upgrades and as to how to connect them?
I can follow instructions but I'm not an electronics engineer!

Any takers for this one please?

---

Probably not worth the effort IMO but if you want to experiment this will help ;)

http://www.hificollective.co.uk/pdf/diode.pdf

Only just noticed your reply. Thank you very much. I might go ahead with the replacement of bridge rectifiers, but it already sounds so good now it has settled down. I had replaced all the electrolytics, and the valves, and the output leads were changed for pure silver wire. (just for the hell of it)

Well you might as well... It'll be the icing on the cake ! I've found it gives a subjectively lower noise floor but as with everything YMMV.

Just bought a well looked after CSA 28 model. Sounds great but I too will upgrade the caps in the future.
Just wondered is there any way to tell an approximate date of manufacture?

Hi Liam


The Copland 266 does respond well to a few little changes, a nice solid musical sound with no edges at all.

Over the years we must have seen around 30 or so of these units.

The image below is our basic upgrade on this player, though I miscalculated the current required on the circuit using the Jung style regulator it need a 1.2 amp device rather than a 500ma max SMT i/c. which also feeds the front panel so just watch that.

There is plenty more you can do in conjunction as well.

Though this basic upgrades do reap quantifiable rewards Liam.

http://www.coherent-systems.co.uk/im...d266stage1.jpg