RandomBass

I have an SX P-bass if you are interested. I'm sure we could work something out. Cheers Geoff Edit: Oops sorry its not a leftie.... doh!

[quote name='icastle' timestamp='1362938880' post='2006465'] Even better when you realise these are secondhand screws... You'll have to excuse me now, I'm just gonna get my collection of used tap washers listed... [/quote] Are these original or re-issue tap washers? Up for any trades? I have a couple of roadworn picks somewhere....

[quote name='Horizontalste' timestamp='1362669245' post='2003095'] I picked up my 1024 at Christmas for 350 with a case, It's an awesome bass and a bargain to boot. [/quote] Crikey that's a deal and a half mate. Why can't I find them lol.

One last bit from me...I promise lol. Just back from band practice and the AH200 was perfect. Loud, clear and punchy with a slight peak around 100Hz on the graphic and dropping the low end, through an ABM410. Heatsink got pretty hot a couple of times, but not unbearable to touch. I'm happy. Well worth the £50 in parts and a couple of evenings investigating/discovering/work/fun.

I picked up a s/h BB414 off here late last year. I have to echo the comments made above really. I'd like to try a 1024 to see if there is much of an improvement - I can't afford the 2024 but the 1024 might be do-able if I can reduce my current stock level Cheers Geoff

Neat diagram. However, the things on the left don't half look like, erm, well how can I put it...? Or is it just me?

As a slight aside, the guy who sold me the amp has offered to pay the cost of the replacement parts, which is a kind thought. As a gesture of Basschat goodwill I thought going 50/50 would be ideal. Cheers Geoff

IIRC the AH150 is also very very similar design-wise. A half-decent tech should be able to diagnose and repair it, no worries. If the problem is the output stage, although the original power MOSFETs are no longer in production, there are several alternatives available which will do the job perfectly - not just the BUZ901/6 that I chose. Make sure they also renew the insulating washers and heatsink compound - it's a pennies job worth doing while the trannies are off.

Yeah thanks for that, thought I'd share my experience to maybe help others on here. Having studied these Clive Button designs, they are pretty straightforward to fix and keep chugging along.

1989 vintage Trace Elliot AH200 GP12 Amp Repair My first contribution in the Repair & Tech forum, but thought I'd share this experience. I recently bought this on BC for what I considered a good price, from a nice chap. Unfortunately it very soon developed a problem which obviously was quite a disappointment, but which enabled me to reawaken my dormant electronics skills. I asked the seller what had been done during a recent service - apparently a few caps needed replacing. He also had one of the 1/4" jacks replaced with a speakon (which is a good mod actually). So what was the problem? Simple really - the output sound was heavily distorted, and the output level was fading in and out. The headphone output seemed fine, which I assumed came from the preamp, which kinda isolated the problem to the output stage. The DI was fine too. So, an evening on Google came up with the schematics together with a wealth of other information, out came my DMM and I reinstalled xoscope onto my trusty Linux lappy to monitor various points around the amp, after having removed the lid of course lol. Signal and supply readings throughout the circuit seemed fine, and I couldn't detect any crosssover distortion at the output. Now here's the odd thing - having the schematic in my hands, I was clearly wrong about the headphone output: it's taken from the output of the power transistors (through a wirewound resistor), although the initial symptoms would suggest otherwise. And something else: when I used the headphones without a speaker load connected, the sound through the phones was fine: as soon as the speaker load was connected the distortion came back through both speaker and phones. Remove the speaker load, and all is well again. My 8 Ohm dummy load had the same effect. This is all pointing to the heavy current side of things. The output MOSFETS were not open or shorted, they didn't seem to exhibit any unusual readings when tested in situ, although best tested out of circuit of course. The power supply had a solid voltage, and wasn't dipping under load (well, nothing that I would consider worrying), but clearly as soon as proper current flow was required, the amp had problems. A little more time spent on Google came up with an identical set of symptoms with an AH300 which basically has the same output stage, supplanted by a beefier PSU, cooling fan etc. Apparently replacing the MOSFETS solved the problem, so lets take a chance..... The original Hitachi 2SK135/2SJ50 output MOSFET pairs were still in place. These are now obsolete so I decided to go for Semelab BUZ901/906 alternatives, which may or may not require a little rebiasing. Farnell delivered in a timely fashion, complete with new mica washers, spacers, heatsink compound etc. A couple of hours of careful component replacement and comprehensive testing last night, I now have a fully functioning AH200. I didn't even need to touch the bias trim pot, which was nice, not a Trace (lol) of crossover distortion. Tomorrow is rehearsal night, so that'll be the real test - proper volume levels! So far, I'm jolly pleased, but with fingers crossed for tomorrow... Cheers Geoff

[quote name='TheGreek' timestamp='1362318968' post='1998283'] Thanks fellas..I just paid £12 for 4 from Tescos... as the saying goes.."we're all geniuses with hindsight.." [/quote] How much? Blimey. Definitely not their 'Value' horsemeat specials there then...

Hybrid rechargeables for me. Don't lose charge when not in use, and haven't needed to buy a PP3 or AAs for a few years.

[quote name='stevie' timestamp='1361564839' post='1987796'] Well, Random, maybe it's never happened before but I'm sure you'll get over it. I did provide an explanation of why I thought you were mistaken and you're welcome to disagree. I've aired my concerns and we'll see if any information is forthcoming. Yes, the advertising thing does bug me a bit, especially when it gets excessive. If I'm having a pint in a pub, the last think I want is somebody trying to sell me insurance or flashing their corporate logo at me. But I never used the word 'wrong'. I do think it would be a good idea for Basschat to charge companies for displaying their business logo. That way at least Basschat would benefit. [/quote] But that's the point. They didn't come to you, you went to them. And you did use the word 'wrong'. Anyway, finally, I respect your view, just not your method of delivery.

[quote name='discreet' timestamp='1361841963' post='1991916'] Don't find that funny at all. Obviously we're poles apart. [/quote] Yes, it must be a North - South thing... Sorry lol...

I'm sorry I don't have anything to help here, but I was just attracted by the thread title...

Everyone will be relieved to know that the Mike Lull review has finally turned up. Hoorah! We can all sleep soundly now lol.

My freebie pack turned up this morning. The stand looks good for gigs, the tuner is brilliant and another cable is never refused. However, I think the kids can have the bag...

Howdy Dave Welcome aboard - it's a pretty cool place and mostly friendly people here. Enjoy! Geoff

[quote name='discreet' timestamp='1361615667' post='1988238'] Bob didn't use the site a fair bit after all... [/quote] Ha that got me - only after seeing your post discreet did I check the original thread date lol. I guess he found someone...

My opinion is wrong? Oh dear. Anyway, perhaps you should address your concerns directly to the horse's mouth - you may get a response. Even if it is wrong. Re the advertising thing, there are members here who advertise their products or services in their signature - so every single post counts. I don't have a problem with it. Is that wrong too?

I'm fine thanks, I've just eaten.