early to mid 70's laney 60 on the bench - now w/ schematic

[DummyLoad]

about a 1972 model - guessing.


high res shots here:


https://www.dropbox.com/sh/a8hjurzb4zh50fb/AADTpQRmV12ziMqB3nOkGopNa?dl=0


output tubes arced, needs cap job. seems like it took a spill - PT mount is cracked and missing mounting bolt, choke was bent. missing board mount hardware.


cool vintage partridge iron,mustard caps, etc.


awaiting owner reply for go/no go on the resurrection... it's not going to be cheap.


--pete

[Willabe]

awaiting owner reply for go/no go on the resurrection... it's not going to be cheap.

Maybe so, but it's in great hands.


          Brad   

[DummyLoad]

thanks brad!     


hoping he says yes... if hes does it's going to be a cool project: i haven't restored anything substantial in almost a decade now.

 
--pete

[kagliostro]

Ciao Pete

Is this the schematic ?



Franco

[DummyLoad]

k, no it isn't. the power supply and output stage are very similar, however, this amp has 3 preamp tubes: 2 x ecc83 and the PI is ecc82.


--pete

[kagliostro]

Ah, OK, one other version


effectively I was surprised seeing the 3 ecc83 + PI


Ciao


Franco

[DummyLoad]

hit a snag... the original PT was swapped out at some time with a 230V 240V unit. that explains the missing transformer bolt/nut, the sloppy wiring of the PT, as will as the missing wires on the PT volt selector patch. also, this amp still has the UK AC power cord.

just sent word to the owner... he's probably going to decline the restoration now. :-\

--pete

[eleventeen]

You're characterizing this as a major major job. It doesn't seem like it to me, but maybe/obviously I am not seeing it as you do. Is this destined for 120 VAC operation?


Replace octal sockets
Replace power trans if necessary or buy klutzy 120 > 240 external tranny
cap job (absolutely to be expected for an amp of this age)
AC cord
Some time on general corrosion cleanup wrt pots, jacks, etc;
Maybe he has to buy new tubes.


OK, the whole thing is a fair pile of money maybe getting onto $500 P+L but it's a total zero unless you do the work to revive it.  The cost of new tubes and new caps, that's just life.

[Ritchie200]

Pete,
Does it have the "Supergroup" stamp on it?  If not, that would put it at 69-70.  This is one of the best sounding amps I have ever played.  Put a treble booster in front, dime it, and it is Tony Iommi in a box - his exact early to mid 70's setup.
If he gives up on it, you may want to buy it.  I guarantee you will like it!

Jim

[Ritchie200]

Franco,

The Klipp was not a very good sounding amp to most people. It pretty much killed Laney in the late 70's.  Most people thought it was too solid state fizzy and the clean channel was just boring.  I played one in a music store back then and was not impressed.  600v on the EL34 plates required good tubes.

Jim

edit: Kind of reminded me of the Lab amps of that same time period.  LOADS of boring headroom with kind of a flat response.

[DummyLoad]

Pete,
Does it have the "Supergroup" stamp on it?  If not, that would put it at 69-70.    Put a treble booster in front, dime it, and it is Tony Iommi in a box - his exact early to mid 70's setup.
If he gives up on it, you may want to buy it.  I guarantee you will like it!

Jim

cool! thanks for that info jim. no supergroup stamp. serial number is on a plate not on the chassis. it's definitely something worth restoring. i'm really trying to push him into getting a mercury magnetics exact replacement, however they're quoting $297 for a replacement. B+ is reportedly over 600V and i have a pair of newsed XF2 mullards that would work really well in it.

This is one of the best sounding amps I have ever played.

why don't we clone it then? i just uploaded some decent shots of the backside of the board. i cannot seem to find a schematic. hoping you have one? if not i'll spend the 2-3 hours needed to reverse engineer it.

--pete

[DummyLoad]

You're characterizing this as a major major job. It doesn't seem like it to me, but maybe/obviously I am not seeing it as you do. Is this destined for 120 VAC operation?

you're making assumptions with that statement.


yes, 120V.


--pete

[Glennjeff]

This definitely needs to be cloned   

I would help but it's a bit difficult without having the amp in front of me, shots of whole cct board (front and back) and the wiring to tube sockets and board photo in high def would be needed.

[DummyLoad]

the first post has a link to dropbox shared folder with high res pics. i'll be adding more later.

when the sign-in window appears and you don't have a dropbox account or you don't want to register, just close the dialog box by clicking the "x". you can still view the pics after closing the sign-in window.

--pete

[kagliostro]

Ciao Pete, just to clarify

has the UK AC power cord

That isn't an UK AC power cord, it is a german schuko power cord, often used also in Italy, here we simply call it german plug
(it assure a very good connection to line)



in UK AC power cord must be not reversible and must have an integrated fuse, like this
(they have strict rules about the color of phase - neutral and ground wires and disposition of the same on the outlet)



May be this can help on finding the provenience of the amp (provided that it is of interest)

Franco

[DummyLoad]

k thanks for the enlightenment on that plug. 

--pete

[kagliostro]

I hope this didn't sound to your ears as I would correct you, if so, I apologize

I have just think it may be of some help on identifying the provenance of the amp

Franco

[Glennjeff]

Well,

The PI looks like a fairly stamdard lomg tail pair, 82k and 100k plate R's with 0.1uF coupling caps to PA grounded through 220k's.

Input/NFB side of PI is AC coupled with 0.1 and 0.022.
Cathode/Grid bias for PI looks like 470 ohm, 1 M X2 and 10k.
There is an plate/plate HF bypass ceramic cap that I can't read the value of. Perhaps 470pF.

[VMS]

I think it's a plexi with few different value components.

Preamp is probably pretty close to this one:

http://drtube.com/schematics/laney/Super_Group_100_Mk1_preamp.pdf

[DummyLoad]

I hope this didn't sound to your ears as I would correct you, if so, I apologize

I have just think it may be of some help on identifying the provenance of the amp

Franco

k, no apology needed. none at all. as always, thank you for all the input.   


origins? well it seems that it was last used in germany. other than that, i have no idea. i'm trying to get some more background on it from the owner.


VMS, yes, it does seem to be a plexi-ish thing.


--pete

[Ritchie200]

Similar design, with a few important differences.   Choke (have to go back to a JTM), big plate voltage (even the early plexi's weren't this hot), darker tone (It doesnt have that Marshall treble notch).  THe breakup when pushed is a thing of beauty.  They got this one right.


I think Ive got that schemo around here somewhere, I just dont have time to look.  Ill see what I can do.


Jim

[VMS]

reverb.com has got great pictures on 1969 60W laney:

http://rvrb.io/1969-supergroup-ecp

[kagliostro]

Those photo are really fine


 


Franco

[Ritchie200]

Oh crap, the guy took it down.  He was from germany and drew one up - looked really good.  They used to call them LBO's (lead, bass, organ). 


Jim

[DummyLoad]

i posted some more detailed shots of the turret board. there are 4 high res. overlapping shots - they're dated 5/21. sorry i missed them, i thought i had posted them with the turret board underside shots. getting old... :-\


--pete


https://www.dropbox.com/sh/a8hjurzb4zh50fb/AADTpQRmV12ziMqB3nOkGopNa?dl=0

[DummyLoad]

the amp is done. 

B+ is 500VNL with 480V tubes loaded at idle @ 120V60Hz line. -Vg is ~ 38V @ ~68mA for both tubes. Vg2 is 462V;457V after the 470Rs. i'll post telemetry tomorrow. the replacement PT is a JCM800 from heyboer. i used the brackets off of the original PT to save the chassis from 4 unnecessary new holes. the outer insulation paper was unprotected so i painted the paper insulation with polyurethane. this amp is now good for another lifetime. it's owned by an aspiring young musician who is enamored with tony iommi.

it does sound really good. testing/playing through a single 12" open back is probably the shortcoming. pics below are a couple of days old. the 10K grid stoppers are there...and everything's tacked down. ;-)

--pete

[TIMBO]

Nice work pete.
The old amps cop a beating over their years, but put a bit of TLC into them and they sound better than ever.

This is a project I have to tackle at some time.
Lots of surface rust, which i'll have to sandblast. This will mean that i'll have to dismantle the whole amp to clean it.
The circuit board is bolted the chassis with a cardboard insulator and it is broken around the bolts and so on and so on.

[DummyLoad]

eek! timbo, i think i need a tetanus shot just for looking at it!

you'll do her up quite well; you always do. :-)

--pete

[Ed_Chambley]

Another one back to life.   Great job DL!  I really love those old Laney's and Sabbath tones.  If I was a young player I would have been thrilled too.

[DummyLoad]

reverse engineered this amp today. some nice storms rolled through while i was drawing it up. nice lightning flash with a crack/boom! lights out just as i was starting to draw the PI. no power for 4hrs. went and got coffee.


schematic attached.



--pete

[DummyLoad]

heyboer has agreed to wind a 800VCT @ 225mA 6.3VCT @ 5A 50/60Hz 120/220/230/240V primaries as a replacement PT with similar form-factor. they quote 5-6 weeks turn-around. currently the heyboer jcm800 replacement PT the B+ is 435V - not as much as i was expecting. idle is 60mA for both tubes.


--pete

[DummyLoad]

received the heyboer replacement PT 8/18 finished it today. nice sounding amp overall. ended up with 525V B+ loaded. 545V unloaded. right where i want it.  bias is at -41.7V. ht fuse holder terminal was cracked and this go-round finished it off: i didn't have a 5x20 fuse holder, so subbed in a 3AG for now.


miscommunication with heyboer resulted in a part that was minus the filament winding CT, so i tacked in virtual ct. i ended up using the original PT end-bells to lay-down PT as was originally. if you use the heyboer end-bells you will have to stand up the PT as it is designed it does fit on end as well: there are no clearance issues with the PT standing up loaded in the cabinet. since the bobbin is exposed i sealed the outer paper insulation with clear polyurethane. lastly, heyboer also terminated the primary with two black wires: white, black, black/yellow, black, back/red. ohm meter and test confirmed the correct tap order. i communicated this to them, so if you order HTS-12134 you'll get a laney 60 replacement PT with the corrections.   


using a pair of svetlana EL34, telemetry taken with a 12AX7 stuffed in V3. it sounds much better with the 12AX7 in V3.


updated schematic attached, link to finished pics.


https://www.dropbox.com/sh/onx5x6awrqv4m2w/AADVCrOzyTYLnY2IgLYNsmtua?dl=0


--pete

[2deaf]

Should the Vol. pots be connected to ground?

[Willabe]

Very nice work Pete! 

[DummyLoad]

Should the Vol. pots be connected to ground?

of course. thanks for the proof. i missed that.


--pete

[DummyLoad]

Very nice work Pete! 

thanks brad!


--pete

[Paul1453]

Lots of surface rust, which i'll have to sandblast. This will mean that i'll have to dismantle the whole amp to clean it.

If you do dismantle the whole amp and don't have easy access to a sandblaster, I have soaked the rusty parts in hot soapy water with CLR (Calcium, Lime, Rust Remover) added.  It seems to get rid of most light surface rust.  Anything that is real deep, after the first soak I hit with some sandpaper to try to get down close to the metal and give her another soak.  I am not looking to make it perfect, only to remove what I can easily and cheaply.  For me, it seems to work reasonably well to clean things up and halt the spread of rust.

[Ritchie200]

That's a great tip/Hint from Heloise!  I use CLR on everything around the house and never thought about using it on a chassis.  Thanks for the suggestion Paul!

Jim

[Paul1453]

That's a great tip/Hint from Heloise!  I use CLR on everything around the house and never thought about using it on a chassis.  Thanks for the suggestion Paul!

Jim

Since you already use CLR you know it is a pretty strong chemical.  Others may not realize this. 

You need to follow the recommended safety procedures for personal protection. 
Undiluted it will chemically burn your skin, and I would hate to think of what would happen if it sprayed back in your face and got in your eyes or nose.

Undiluted it could also have a violent chemical reaction with certain substances.   

Caution is advised and I wouldn't recommend using it undiluted, it is too strong that way.
It is quite effective in cleaning things if used safely.

[helpdeskeddy]

reverse engineered this amp today.
schematic attached.

--pete

Hey Pete, thanks for putting the schematics online.
I'm working here on the same Laney supergroup 60... It's been modified with (London City?) transformers and a switchable high gain channel... why do people wreck these beautiful amps??
Anyway, I've got a working example next to it (it's my brother's). It's got a few alterations to your schematic:
- the bias is adjustable: a 33k resistor in series with a 50k potmeter (instead of the 56k at Bias A)
- the resistor of the first treble input is 56K instead of 68k

Did you make any other changes to the schematics? Could you put the latest version online?

I've tracked down the Partridge transformers, but they're for a 100W supergroup.
Does anybody know the color codes of these transformers?
(2 yellow / 2 black on primary side + 2 black / 2 brown / 2 green / 2 blue on secondary side)
I'm hoping it has a 4 ohm tap...
(maybe I'd better start a new topic for the second question??)

Regards, Eddy

[DummyLoad]

about a 1972 model - guessing.


high res shots here:


https://www.dropbox.com/sh/a8hjurzb4zh50fb/AADTpQRmV12ziMqB3nOkGopNa?dl=0


output tubes arced, needs cap job. seems like it took a spill - PT mount is cracked and missing mounting bolt, choke was bent. missing board mount hardware.


cool vintage partridge iron,mustard caps, etc.


awaiting owner reply for go/no go on the resurrection... it's not going to be cheap.


--pete

Another Forum member (Vlada) requested a link refresh to the pictures before and after restoration.

Also, attached corrected schema.

https://www.dropbox.com/sh/7nmk3gx5ed2nokg/AADIIfctbCuuzEYF7fWF1Jt3a?dl=0

--Pete