Advice on a 70's Laney Supergroup

bodhi

I have this old 100W Laney pre-Supergroup head (I believe from the early 70's) which I bought in 1992, if I remember correctly.

It's a long story, but the amp isn't with me and haven't been for more than 20 years.  But now I'm feeling keen to finally get it shipped over to the UK.  It's recently been serviced by a retired Laney engineer, so I know it's currently in working condition.

So I was thinking about it today and looking at some pics I have, and I realised that I had no clue on how to use it safely and properly anymore.  At the time I had two cabs of unknown and rather questionable origin and just plugged in and turned it up and somehow managed to not fry the whole lot.  I'm sure it sounded crap with my home-made "Flying V" with its acoustic pickup, but damn - was it ever so LOUD?  Hell, yes - you bet.

Is there anyone here who could help me decipher and perhaps even understand it all again?

For example, and this is going to show how little I know:

Is this a two channel amp, with two inputs per channel?  Why two per channel?

Do the channels share the EQ section?

Gain One and Gain Two - one per channel?

What would the correct voltage selector switch position be for the UK?  230?  250?

Speaker matching selector - 3, 8, 15?  So to connect it to a cab with an 8ohm speaker, set it to 8 - but would it be ok to connect to just one cab?  Change the selector to something else if connecting to two 8ohm speaker cabs?

The difference between the two fuses?

Is the Output connector to connect it to a slave amp type thing?

I apologize sincerely for not knowing...very embarrassing, actually.  If I had a manual I would certainly have read it before asking.  Would appreciate any help.

Some pics:

ICBM

If that's been serviced by a "retired Laney engineer" then it's a good thing he's retired and a bad one he's still working on amps! That mains connection is dangerous and *must* be repaired properly before you use the amp, unless you want to risk frying yourself. Get the correct modern IEC socket from Tube Amp Doctor and have it replaced properly.

http://www.tubeampdoctor.com/de/shop_Kabel_Steckverbinder_Steckverbinder/IEC_Kaltgeraetenetzeinbaubuchse_mit_Einbaumassen_der_Bulgin_Pig_Nose_Buchsen_318

(In Germany, but they ship to the UK - there may be a UK supplier of the same thing but I'm not sure, and it is *not the same* as a standard IEC socket which will not fit properly.)

Given that I would want the amp looked at by someone else who knows what they're doing anyway...

bodhi said:

Is this a two channel amp, with two inputs per channel?  Why two per channel?

Yes, two channels. The two inputs are a 'high' and a 'low' input for better matching different guitars, or so you can connect two instruments to each channel, or so you can 'daisy chain' more than one amp together.

bodhi said:

Do the channels share the EQ section?

Gain One and Gain Two - one per channel?

Yes and yes.

bodhi said:

What would the correct voltage selector switch position be for the UK?  230?  250?

250. Although the EU has supposedly harmonised the voltages at 230V, they haven't really - it's just a different way of defining them. The true UK voltage is still 240V, and you should always set the selector *above* the expected voltage, not below. If the amp is getting slightly less voltage than the selector says, it will run cooler and more reliably.

If you're having the amp serviced it's good practice to disconnect a finger-adjustable selector like this now.

bodhi said:

Speaker matching selector - 3, 8, 15?  So to connect it to a cab with an 8ohm speaker, set it to 8 - but would it be ok to connect to just one cab?  Change the selector to something else if connecting to two 8ohm speaker cabs?

It's OK to connect either one or two cabs. If one cab, set the selector to the same as the cab. If two cabs, set it to 8 ohms if it's two 16-ohm cabs, or 3 ohms for two 8-ohm cabs. (Or 3 ohms for any other combination - it is safe to use different impedances as long as you do this.) 3 and 15 are the same thing as 4 and 16, it's just Laney being non-standard.

bodhi said:

The difference between the two fuses?

One is the 'mains' (power input to the amp, shuts down everything) and the other is the 'HT' (high tension, shuts down the high-voltage supply to the valves but not the 'heaters'). Make sure the values are correct! Often you find larger fuses fitted to old amps. They should usually be slow-blow or 'T' fuses. A valve failure will usually blow the HT fuse, a blown mains fuse is usually (but not aways) the sign of something more serious.

bodhi said:

Is the Output connector to connect it to a slave amp type thing?

Yes.

bodhi said:

I apologize sincerely for not knowing...very embarrassing, actually.

Don't ever apologise for not knowing something .

Embarrassing is doing something stupid and breaking it because you didn't ask first when you didn't know .

Hope that helps!

Lew

Fun amps if ya can get em over 4 :-) Looks like it's been retolexed. Try not to kill yerself!

DJH83004

Well ICBM at least it solves the Bulgin plug legality issue! just solder the mains lead straight to the pins 

ICBM

DJH83004 said:

Well ICBM at least it solves the Bulgin plug legality issue! just solder the mains lead straight to the pins 

lol

And tie a knot inside the broken Bulgin so it can't get pulled out or rotated and break the wires… sort of. Not.

Still, better than an old Marshall I saw once where the mains cable had been simply taken in under the edge of the chassis, which was clamped down onto it and had started to cut through the plastic!

Sometimes you do wonder how more guitarists aren't electrocuted.

bodhi

Many thanks for the replies!

To be fair - the pictures I posted were taken in 2011, so don't accurately reflect the current state of the amp.

Appreciate your concern for my well-being, too

bodhi

Lew said:

Fun amps if ya can get em over 4 :-) Looks like it's been retolexed. Try not to kill yerself!

You can easily get them over 4 - if you stand very, very, very far away

Lew

bodhi said:

Lew said:

Fun amps if ya can get em over 4 :-) Looks like it's been retolexed. Try not to kill yerself!

You can easily get them over 4 - if you stand very, very, very far away

Haha long cables and doors with a gap at the bottom help.

impmann

GREAT amps - monster loud and the building blocks for the sound of Heavy Metal. The mighty Sabbath used these amps back in the day on the early albums/live performances, admittedly with treble boosters and Octave Fuzz pedals in front of them to give them a bit of a kick in the plums.

They also sound great clean - well, clean ish. I gigged one about 20 years ago for a couple of weeks whilst my amp was being fixed - these old Supergroups were worth two-thirds of bugger all back then so the rehearsal rooms leant me the amp. I think it had been left behind by another band, anyway!!

Trotter

As others have said, fabulous amps these. Have used one a lot whilst recording. far more useable than some of the big name brands from the era imo. have fun

Lew

Superbass innit yo