Count Bassie

Med Zeppelin

Fad Company

The Harkness

Meat Leaf

42 minutes ago, Obrienp said:

Cool looking bass! One you would actually want to own and play.

 

Mine was a short scale Vox. I think it was called a Clubman or similar. It had two surfy looking chrome covered pickups and an ashtray bridge cover. It got off loaded onto me by a school friend who had decided he wanted to play drums instead. I had not idea about scale lengths, truss rods, or intonation. I remember it being horrendously out most of the time but I had no idea how to fix it. After leaving that school band, I didn’t touch a bass again until I was in my 60s, the experience was so traumatic. I definitely would not want to buy that bass back! 
 

 

Glad you made it back around!

Thanks @BassBodfor the Stuart Watson rec, we have corresponded and I'm going to get my tech guy to have a chat with him. At this point the amp has been brought back to the bench, opened up and its contents partially laid out on a piece of plywood...

I'm hoping this comes to a happy end soon. 

I'll post when it's up and running. I'm saving my 135 lb Ampeg PR410HLF for it... 🙂

On 06/09/2025 at 17:15, BassBod said:

The name I recall for the earlier designs was Stuart Watson? 

I'll look him up! Thanks!

On 06/09/2025 at 17:10, BassBod said:

Just a thought, but I still use MkIV GP11 preamps - the preamp gain usually has to be on 7 or 8 out of 10 clicks with any passive bass.  There is a lot of headroom, I guess to suit higher output active basses of the time.  No shortage of output on the master volume, but the preamp gain generally needs to be high.

It's still in pieces, back in the bench after feeling it wouldn't get loud enough. 

Getting it back pretty soon for another run...

She Kinks

Raul Butterfield

Nickie Fixx

Fete Way

31 minutes ago, Baloney Balderdash said:

Just got the ESP/LTD B4JR bass in the door that I bought used Friday yesterday.

It's a just 28.5" scale length short scale, with a Basswood body, and a Maple neck with Rosewood fretboard.

And after a thorough setup, and having the stock pickups, which honestly sounded decent enough, for an EMG Geezer P pickup, it sounds non less than amazing.

Really nice tone, both finger plucked and using a pick, and the sustain is pretty substantial too.

Even the low E sounds great, despite the short scale length.

It's also very light, the body being made of Basswood, which does make it prone to neck dive, but nothing a wide grapy strap can't solve.

Now the bad things, when I got it it had one of the most horrible setups I ever saw, and with loose input jack socket, that was easily fixed though, however the nut slots are cut way too high, and it got some pretty sharp fret ends, that you can literally cut your hand on if you are not careful, and will probably have fixed that too at some point by a proper luthier.

The thin U shaped neck will also take some getting used to, it is not exactly beefy, but it kind of feels that way, because the neck profile is so round.

The frets are not perfectly leveled leveled, but still well enough that I can get it to my preferred string action (about 2mm (~5/64") low E string at 12th fret) without any issues or string buzz whatsoever.

Truss rod works as it is supposed to, and neck seems stable.

Tuners are not the best, but they work just fine.

Here it is (excuse me for my old crappy digital camera):

 

I got it for what equals about 30£, a deal I could simply not pass.

 

That's a little booger! Cool that it's nicely proportioned though. Get those fret sprouts filed though... Not cool to bleed all over the carpet! 😁

I think this game could be more fun if another rule were added.

Ruth

Kush

6 minutes ago, SimonK said:

 

Yes - sorry I don't have anything prior to Mk V but I thought there could be some similarities.

You know there might be more than I've been led to believe, but it's possible this amp had been serviced with non-spec'd or alternate parts- which might have to do with why the output is so anemic. I'm not the tech though, and life's too short for some things...

Also, as far as I've been able to find, there seems to be no Mk IV schematic in existence. ? Trace Elliot has a rabbit hole of hardly documented work.

Thanks again for the files though!

15 minutes ago, prowla said:

I don't think it was an AH150, as that had quite a shallow depth.

Ah - the pics show it has a UV tube too, so that rules it out anyway.

Yes, this one's a 250.

1 hour ago, SimonK said:

Trace-Elliot GP11 schematics+parts list.pdf 930.45 kB · 1 download

Yep, this set goes back to the Mk V, and there are some significant differences between it and the Mk IV.

Thank you for sending those though! I've downloaded them and I'll bet there will be another old tank added to the pile within the year, 😁. 👍

3 hours ago, Matt P said:

I've just had my mk4 serviced by Martin @Stoneham they might have some useful information? 

 

Matt

I'm all about it, I'll look them up. Thanks again Matt!

(Sent him a mssg... Ashdown, Peavey and BAS next...)

3 hours ago, Stub Mandrel said:

 

The GP11 mk iv won't be very different from the mk 5.

Apparently there are some meaningful differences. The MK IV diverged from the MK V in the preamp I think, that's the report. He's been, as I say, reverse-engineering his way through some of it. 

I'm hoping to eventually get to someone who was part of the design team from that period.

Alright then...

My tech has the amp opened up again, as the volume doesn't seem to be what it should. 

Apparently the signal travels from several points between the power section and the preamp, and the preamp is quite complicated. 

At this point the gain on the preamp has to be all the way up to get even moderately significant volume. The model I have, the MK IV, doesn't have a schematic or any kind of plan available, so I'm starting to dig in and see if I can talk to any of the people who had a hand in the early designs. 

So far my tech has been essentially reverse-engineering his way through the amp, and it's exhaustive. 

I'd be very interested in hearing about any sources of first-hand info about the MK IV'S design. 

Thanks! 

It's off to Ashdown...

Ready to receive... Went with gloss black, Rust-Oleum clear lacquer and #0000 steel wool. 

So it's been cleaned up, which took a lot more work than anticipated. The fan was caked with some kind of mud or sludge, and the preamp module was taken apart and gone through methodically. I almost didn't want to know what went on in the life of the guy who owned it previously...

Anyway it's working, but it's not putting out nearly the power it ought to be. The tech has it back again, and is going through the op amps that get signal from the power supply. 

It's got a surprisingly small power amp I'm told, due to the structure of this thing. It seems the 250 through 500 models used the same transformer and big blue caps, but the number of power transistors was the difference in the final product. 

But, it sounds like I expected it to, which is great... Hopefully the output comes up to spec, and I'll install it into the sleeve. 

Pix to prove it happened!

(Typos fixed!)

20 hours ago, Jean-Luc Pickguard said:

 

Simply Ned

Simply Redo

Depeche Mole

Modness 

The Cart

The Sax Pistols

3 hours ago, BassmanPaul said:

Don't worry Bro - we'll help you find it again!!

 

Oh boy! Popcorn time! 😃