Friday, 17 February 2012

Peavey Firebass 700 - Cleaning and Gutshots

After much struggling I got the innards out of the Firebass 700 head. Not helped by some pretty obtuse bolting and a stupidly heavy transformer.

Basically I needed to give the pots a clean as they were pretty noisy so this meant having to be able to get at the pots and spray them with contact cleaner.

Contact Cleaner

Firebass 700 - Front Chassis 1

Firebass 700 - Front Chassis 2

Also decided to take the back part of the chassis out, having discovered it's basically two parts, just to be nosy.

Peavey Firebass 700 - Rear Chassis

And here's the clever bolting, which is actually the bolt that holds the top carry handle on (there's a similar one at the other end).

Troublesome Bolt

Need to do some more cleaning some time, paintbrush and vacuum cleaner job, to get rid of all the dust on the inside but that's a job for another day.

Tuesday, 14 February 2012

Harley Benton GA5 - Master Volume Kit

Got this in the post today.

It's a simple kit, supplied by AlnicoMagnet on eBay, to modify a Harley Benton GA5 or Epiphone Valve Junior for proper master volume functionality; meaning that the pre and power amp stages have their own volume controls thus allowing greater control over the sound.

Friday, 10 February 2012

B.Y.O.C. Ego Boost...

See what I did there?

Random internet person has used my B.Y.O.C. Confidence Booster as an example of How It Should Be Done.

This pleases me. Now I need to save up for another B.Y.O.C. kit so that I may do more awesome soldering.

Peavey Roadmaster - Troubleshooting pt. 1

My Peavey Roadmaster head still has its original valves, the thing is nearly 30 years old and being a hard rockin' bad ass or something I tend to push it quite hard.

When I was playing through it yesterday I noticed that the pre-amp overdrive had taken on a fuzzy, glitchy quality. which did sound very cool but as valve amps are supposed to give you nice, warm, smooth sounds was probably cause for concern.

One quick consultation with Mr. Foxen later and it's probable that at least one of the pre-amp valves is dying. Luckily the Harley Benton GA5 head takes the same type of pre-amp valve (12AX7) so I have an easily accessable test rig for checking the valves.

Peavey Roadmaster - Front Panel Removed

Harley Benton GA5 - Chassis

So that's what I do... a quick check of each valve in the GA5's pre-amp to see if  they're all working fine. And they are. Which is puzzling, so I put them back in the Roadmaster, connect it all up, and switch it on; nice valve-y overdrive soon gives way to glitchy fuzz. There's definitely something wrong here, but I'm puzzled as to what exactly. Perhaps I need to push them harder in the GA5, which would be easier if it were a master volume amp. As it was I had the volume maxed but as I have neighbours I can't really spend ages bashing away because through a 4x12 cab even a 5 watt amp is pretty damned loud.

Wednesday, 8 February 2012

Retrovibe RV4 Coil Split

At some point I'm planning to do a coil split on my Retrovibe RV4 so I can get ALL THE TONES from it.

The question is which method to use for achieving this?

The most obvious is to buy a couple of push/pull pots and use those (plus another one for series/parallel switching). The problem with that is that it costs money and I'm currently an unemployed bum.

The next two options are probably better as I can do them with stuff I have about the house.

First is to utilise one or both tone controls to this end, providing me with a variable coil split on one or both pickups (and either one master tone control, or no tone control) which is better as I can then minutely adjust the perfect sound, instead of the simple one-or-both that straight forward switching offers.

Second (and probably vastly more unusual) is to have, basically, four volume controls; one for each coil. I know this is possible as there are diagrams for using such a set up with single pickup passive MM-style basses. I have no idea whatsoever whether this would be at all worth it, but it'd be an interesting experiment nonetheless.

Wednesday, 1 February 2012

Columbus EB-3 Copy - Taken to bits...

Took the EB-3 copy to bits today to have a look at the pickups and whether the neck pocket was shimmed.

Firstly it turns out the neck pocked was shimmed with a bit of folded copper. Columbus Neck Pocket Copper Neck Shim
(in the background can you can see how much I failed to keep the strings in place using a cable tie)
I've taken this out as I want to replace the bridge on this bass at some point (adjustable intonation FTW) and unless I bugger about installing a Tune-O-Matic style thing and have it set stupidly high I need the shim out so the neck sits at a shallower angle.

When I was over at Mr. Foxen's picking up the Woolly Mammoth clone he mentioned that a lot of cheap '60s knock off instruments featured single coil pickups under humbucker covers, which is something I was vaguely aware of as a friend has an LP copy with the same 'feature' So I took the pickups off and had a look at them and surprise surprise, they're both single coils masquerading as humbuckers.
Columbus Neck Pickup - Back Columbus Neck Pickup - Coil Bridge Pickup - Back

It's not something that's easy to see for the uneducated eye, but compare the above with pics of genuine equivalents.

(Not exactly the same style, but the bridge pickup is based on a Hofner humbucker and this is the closest gut shot I could find)