Laney VA series

Nice score Leftfoot! Glad you're enjoying the amp, and nice to see those gutshots too.
The V1 Mullard could well be the original. From what I can tell, I believe they came from the factory with Mullards in the preamp and RFT output tubes.
Let us know how your tube swaps go!

thanks moritz,

yes your're right V1 is a original Mullard...i leave it in....the other i swaped with older phillips and mullards...1 power tube was a original rft el34 the other noname...

put some big svetlana el34 in! the bias is arround 40mA --> hot!

and it sounds out of space!

the next step is to renew the pot and the cap....but first of all i want the power up the baby!

yeahhh....waiting for the schema...cheers

Are the VA series cathode bias or fixed bias?

i put some cathode bias resistors in and adjust the bias to 40ma....but i think is fixed, because...the range to adjust is not to much....but it works!

So I need to have my amp rebiased when I change my output tubes?

Yeah it's fixed bias, so yes, need to rebias it when swapping output tubes. There's a little hole in the PCB which allows you to access the bias trim pot with a small screwdriver... it should have the word "bias" written next to the hole in silver PCB trace material (it's towards the power transformer side of the PCB).

Any tips when I want to try it myself? (I am aware that there are high voltages present - I've already worked on tube amps, I just don't understand the whole bias thing.)

There's a pretty in-depth sticky topic in the Hints, Tips and Tricks section of this forum which runs through the biasing procedure.

Personally, I always found this a good, consise how-to-bias guide fom the Duncan amp pages (cathode resistor method): http://www.duncanamps.com/technical/lvbias.html

The Aiken amps article on biasing is also very good and goes into greater depth, focussing on plate/cathode current (cathode resistor) method: http://www.aikenamps.com/Biasing.html

I would probably read the Duncan amp pages article first, and then move on to the Aiken amps one. That should pretty much have you covered for biasing...

Yikes!... Someone did well...

http://cgi.ebay.co.uk/Laney-VA100-Lead- ... 2a05b5357b

I'm still looking for a second one...

A second one?! Are you planning to run them in stereo?

No, I just want a 50W version, so I have a lighter one for smaller gigs.

hey guys,

after the honeymoon and a couple of jam session with the amp....i didn't like the sound! the cleans aren't bad at all but the crunchy sound is very bad....its very fuzz! like the laney klipp i think....bahh...

okay, so i did some homework and talk to a couple of friends after ritz send us the schematic.

first of all i changed the copple caps to 47nf on all tube, then changed the hole tonestack to orange OD120 tonestack...and other small thing....because this is a bass amp.
my main goal was to put the bass responds down....

after this work i kicked the amp on....the cleans are miles better...really crispy...BUT the crunch is still bad....

can someone help my out? or can someoen explain me how to use the gain nobs? how they react?

my settings are;

gain 1 --> 9 o'clock
gain 2 --> 12 o'clock

thanks in advance

raffa

I use gain 2 as a channel volume knob (set it once & keep it that way). If you do it like this, the other knob will work like a drive knob.

Edit: Why do you think that it's a bass amp?

because the coupling condenser are with 100n really big! only bass amps use this value!

The cutoff frequency of the coupling capacitors is somewhere around 45 Hz. Sounds quite normal to me. Apart from that, the EQ-network is centered around 500-600 Hz, which is guitar territory.

Hi guys - I have a Laney VA100 combo with a pair of HH speakers. This was sent to me by a customer (I repair guitar amplifiers) but it was apparent that it was going to be a long job to repair so I bought it. In the end, the main problem was a pair of 1N4007 diodes that had been added (why?) to one valve base - strange! After a fair amount of rewiring and new components it is all up and running nicely but the reverb refuses to work! Tank and the drivers and transformers are all good but another curious modification has been made where the reverb driver valve links back into the pre-amp around the phase splitter. An extra fly lead has been added and a copper track broken - once again - why? Has anyone got a photo of the underside of the big circuit board of a combo ( that is - 5 rather than 4 preamp valves) that clearly shows the circuit board tracks?