Laney Schematic Help - Tech advice now

[SLW]

I am looking for a schematic for a Laney "Pro Tube Lead" 50W head.  The owner tells me that it was made before the AOR amps came out in the 80's.  He claims that he can't get any dirt out it and wants me to help figure out why.  While it is labeled "Pro Tube Lead" like the AOR amps it apparently is not an AOR.  The controls on it are Presence, Bass, Middle, Treble, Master Volume and Preamp Volume.  I have seen pictures of it but not the amp itself.  None of the controls are pull pots like on the AOR's.  It seems to be a more simple amp.  The owner thinks it is close to a Marshall 2204.

With all of the experience here I thought someone here might know a little more about the amp and perhaps even have a schematic.  My internet search has come up empty.

SLW

[kagliostro]

I've give a look to my schematic collection, unfortunately I haven't the schematic you are looking for

I've a schematic that looks like the 2204 schematic, but I think that this is a too little likeness  

K

[Ritchie200]

Yeah Kag, I was thinking LC50 too.

SLW, does it have 4 inputs?  Ask the owner to read you the model number on the back of the chassis.

Jim

[SLW]

Thanks for the suggestions everyone.  To answer Jim, There does not appear to be a model or even serial number  on the back of the unit.  What on earth could that mean?  The owner took some photos with his cell phone and sent them to me. The ones of the back are shown below.  The ones of the front are pretty blurry but it looks like there are only two inputs.  Does this ring a bell?

[Ritchie200]

You may have to crack it open to get more info.  Unfortunately the Laney site limits access to their schematics.  I'm not sure what you would need to do to sign up, but may be worth investigating if a model number search came up empty.  However, a phone call to their tech support might get you headed in the right direction.  Good luck!  Oh, and check the effects loop jacks first for tension and crud.  Good spot/cause for limited volume or drive.

Jim

[SLW]

The owner is bringing the amp to me.  I will keep you all updated about what I find.  I guess I will take it home and play it first to see what I think.  I am sure I will have questions for the fine folks on this forum.

SLW

[SLW]

The owner brought the amp to me.  I just finished playing it for about half an hour.  There are only 2 inputs.  The controls are presence, bass, middle, treb, master volume and preamp volume.  There is no effects loop.  The owner asked me if I knew how to put one in.  I plugged my strat into the hi input.  I started out with the preamp on 2.  The amp is quiet.  I test all of the pots.  The presence doesn't seem to do anything.  Everything else is fine.  The owner says that he can't get any dirt out of it.  I go for distortion now.  I turn up the preamp volume to 8 and the strat up to 9.  I hit a power chord and have dirt all over the place.  Sounds pretty good too.  It cleans up with the guitar volume knob.  I can get overdrive to good ole distortion.  I can not get 1980's type of distortion.  I did not try humbuckers.  I have not pulled the chassis. 

I don't think there is anything wrong.  The owner once had a AOR and I think he is looking for that 80's hair metal sound.   

I am not a amp tech.  I am just trying to help the guy out.  He seems a decent fellow and told me to keep it as long as I wanted.  I don't really want to open it up if there is nothing wrong with it.  If it were my amp I would have it apart for curiosity sake.  Would I be out of line if I told the guy that it seems ok to me and to go get a pedal (like a Rat, we all had them) if he wants those sounds?  What would you guys do?  When does it become my problem?  I should have asked about this first.

[HotBluePlates]

...  I don't really want to open it up if there is nothing wrong with it.  ...  Would I be out of line if I told the guy that it seems ok to me and to go get a pedal (like a Rat, we all had them) if he wants those sounds?  What would you guys do?

If it were me, I'd tell the guy the amp is working exactly as is was built to work, and advise him to buy a Rat or one of the other ba-jillion distoriton pedals to get the sound he wants.

Assume for a moment there actually is a problem with his amp: if you can't replicate the problem, how can you fix it?

Assume there is no problem with the amp, but the owner thinks it should sound some way other than it does: you'll likely never make the owner happy, unless he is very experienced and/or you get extremely lucky.

What I mean is you'll be fighting to try to match an idea in his head. *IF* he has played an a range of amps and knows without a doubt that a specific amp does exactly what he needs (and tells you what that is), you'll spend a lot of time guessing wrong and spinning both your wheels. Of course, if he can say "Brand X's model ____ is exactly the sound I'm looking for," there is a logic to telling him to sell the amp he has and buy the one he knows works.

All that said, if you two are good friends and can communicate well (and there is no time crunch), you might be able to go back and forth tweaking the amp to his taste. This really requires time, and someone who can very clearly articulate what they want and how that is different from what they have.

[lowatter]

I recently traded an Epi Dot for a Laney ProTube AOR-30 12 for my son as his first real amp. The guy I got it from complained that the sounds from this amp wasn't what he was looking for. After getting it and messing with it a bit I found that this is a great amp but needs alot of setting adjustments to dial in what the user wants. It's a VERY versatile amp and can sound great for most styles of playing but you have to spend some time with it to get to know it. I really feel that these are diamonds in the rough for what you can get out of them for the price. The presence control doesn't seem to do anything on this amp either but I haven't spent enough time with it yet to want to open it up either.
I realize that this response doesn't have much to do with your request especially since this is a AOR and a 6V6 amp but I wouldn't hesitate to recommend anyone to check them out and to be patient with the settings. It's a great 1st tube amp for an 18 year old for very little moola and my son is loving it soo far.
Here's a Laney forum that I found...
http://www.laney-posse.co.uk/theposse/index.php

[Ritchie200]

I assumed (you know what the means!) from your original post that at one time the amp was doing what he wanted and then something changed.  Now that I re-read your post, that might not be the case?  If he just bought it, expecting it to do something else - then yeah, send it back and tell him to crush the front end.  Or sell it?

Jim

[SLW]

Thanks for the input guys.  I sent the owner an email saying I think the amp is fine and that I don't want to fix what is not broken.  I suggested that he get a pedal for higher gain sounds.  I will let you all know how it goes.

[SLW]

The owner stopped by and we talked about it.  He is happy to hear that the amp seems fine with my guitar at my house.  He thinks that something must be up with his guitar.  He said the guitar pots were scratchy and it cut in and out on him.

He wants an effects loop in the amp.  He is willing to pay for any parts that it would require.  I told him I was willing to explore that option.  He said to keep the amp as long as I want.  I pulled the chassis and started to trace things.  I printed out the schematic for a Marshall 2204 and followed it.  It turns out that it is almost a part for part match for the 2204.  There are a couple of part value differences and the power supply has a couple extra resistors and caps.  I did not unsolder anything since it is working.  I made a schematic.  I am posting it here if anybody else comes across one of these. 

The found C17 is after the presence pot in the Laney.  The leg that was soldered to the back of the pot has come off the back of the pot.  This explains why the presence pot didn't seem to do anything.  I will fix it for him if he wants. 

I will research effects loops and seek opinions in a new post.

Thanks for the advice everybody.

SLW