Laney VC 15 110 schematics

[zbyszekskibinski]

Hello my friends,

Does anyone know where I can get schematics to Laney tube amplifier VC 15 110? I've looked everywhere and I am giving up cos it's nowhere to be found, please help!

thanks Paul

[Bill M]

Hello, Did you trySchematic Heaven - FREE Amp Schematics Tube Amp Schematics Valve Amp Schematics Effect Schematics Effect Pedal Schematics Guitar Amp Schematics Bass Amp Schematics Fender Amp Schematics Marshall Amp Schematics Gibson Amp Schematics Vox Amp Schematics. By the way . What is wrong with your amp?

[zbyszekskibinski]

Hi Bill,

Thanks for your reply

Yes I've tried this website and they don't have this model.
There's nothing wrong with the amp as yet. I've just bought it on e-bay and waiting for delivery. I'm passionate about repairing old and new amps, so I just thought it would be good to have this schematic just in case something wrong happened to it and I had to try fixing it. I've looked at similar models like VC 30 and VC 50 and they have different ways of bias setting. I wanted to know how the bias will be set in the model I'm buying and what are the voltages in different stages of the amp (they are given on schematic diagrams of VC 30 and VC 50 I managed to download from Polish website. I was thinking about slightly 'underbiasing' this amp to get the required sound effect ( just up to the level before the amp starts getting crossover distortion). I've attached both schematics below. In Vc 50 the bias is set by negative voltage passed on the grids of output tubes and adjusted with the variable resistor.

[Bill M]

There is no bias setting on the VC-15. It is cathode biased.

[Enzo]

And when you CONTACTED Laney and ASKED for the schematic, what was their response?

[zbyszekskibinski]

They wouldn't give me schematics saying it's only available for 'electronic engineers'.and that 'they do not normally email them to anyone'

[zbyszekskibinski]

Ok guys. I found schematic diagram here:

http://i153.photobucket.com/albums/s.../VC15small.jpg

although it's not very clear you could see some voltages values in different amp sections. This amp is probably cathode-biased but there is separate voltage supply passed between resistors R51 and R 56 (on the grids of output tubes). I'm not sure what it is but it doesn't seem to be a negative bias voltage. Could it be some 'automatic bias set-up' This fellow I'm buying this amp from is saying that you can replace tubes without rebiasing them as the amp 'rebiases itself on its own' Can you help me with it?

[Alex/Tubewonder]

This is a commonly used way of supplying negative bias voltage to power tube grids. It's not cathode bias.

[Robert M. Martinelli]

The VC15 has an adjustable fixed ( or "external" ) bias, while the VC30 is cathode ( or "self" ) biased ( its output section being a "carbon copy" of an AC30 ).

Cheers

Bob

[zbyszekskibinski]

thanks for all your replies, now I have no doubts it's a typical fixed bias.
Paul

[clear and blue]

i know this is an old thread but if you don't already have the schematics for the VC 15, i can send you them (don't know how best to do it, maybe PM me and i will email the pdf file). in fact, i don't know why they refused you. i have had excellent after sales service from Laney.

although i am trying to learn, i am a complete electronics novice and have found Roger Hickman at Laney to be incredibly helpful and patient with my questions and taken the time to help me understand what must have been the most mundane questions.

received the service guide from him within a day last week and i am by no means a tech. he will probably ask you for your serial number; maybe to be able to send you the right schems for your amp (it changed design slightly a few years ago) or maybe just to see whether you actually have the amp or are just scrounging their design.

PS: great little amp isn't it