drewm

Thanks guys. My medium term plan is to get myself a lighter rig (the combo weighs 30kg - it's great, but solid!). My thought was a to add something like a Markbass 2x10 which I could use with my existing rig immediately, and then as funds allow, pick up a Little Mark III to use with the 2x10 independently. Then further down the line I could move the combo on and add a 15" cab to my new rig. That'd give me a more flexible system with no component weighing more than perhaps 16/17kg.

I have a 1991 Trace Elliot 15" combo of slightly unclear spec, as no manual or record of the 715S model can be tracked down (see [url="http://basschat.co.uk/index.php?showtopic=73211"]http://basschat.co.uk/index.php?showtopic=73211[/url] for the backstory). It's most likely 200W into 4 ohms. The amp has two speaker outputs, labelled Minimum 4 ohms, into one of which is plugged the combo's internal 15". I'd like to add a 2x10 extension cab. As there are two outputs and the minimum load is 4 ohms, my assumption is that in the internal speaker is 8 ohm and I can therefore add an extension cab at 8 ohm to produce a 4 ohm load. Is that a sensible assumption? (And is my maths right?)

Ah, I see, they're little bungs. Head removed, switches cleaned, head replaced. Brilliant. According to the stickers inside, the pre was assembled 19/11/91,and power stage on 20/11/91 and it passed QA checks on 22/11/91. It's not doing too bad for a 19 year old amp. Thanks for the advice. This place is great.

Armed with switch cleaner, I went to open up my Trace Elliot combo to get inside and clean my crackling pots. But I can't figure out how to get the amp head out. There's no screws or anything on the front or rear face. All I can find are what looks like screw covers on the top (see photo) - but they're pretty well stuck down, and I don't want to make a mess of them if they're not the right access point. It's going to be hard to do neatly. Anyone have any ideas? [attachment=49196:te_front.jpg] [attachment=49197:te_top.jpg]

[quote name='obbm' post='709899' date='Jan 12 2010, 12:42 PM']Whichever way I would say it's a 715S, 200-watt into 4-ohms.[/quote] Brilliant. Thanks for all the help!

[quote name='obbm' post='709772' date='Jan 12 2010, 10:19 AM']According to one of my old catalogues the bottom head is an [b]AH2007S[/b] i.e an AH200 with the GP7 pre-amp The 1 x15 combo with that same amp is the 7215[/quote] Ah, thanks for this - but my combo is narrower than the one in your scan. It doesn't have the extra vent spacer panels either side of the preamp. But, that said, it's likely that whatever mine is, it's going to be around the same spec. I'd always had it in my head that this was a 400W amp - although thinking about it, that doesn't make much sense for something this size. I was 15 when I bought it, so that could easily be down to me misunderstanding at the time. If it [i]is[/i] 200W RMS, then it's possible that the sales person quoted me 400W [i]peak[/i] to make it sound more impressive. He also told me that it had be played by Mike Mills of R.E.M. so I think it's a reasonable assumption that the guy was a bit of a wheeler-dealer. ;-) But, most interesting of all, this means that my point of reference for how loud bass amps are has just changed. If what I thought was a 400W amp is actually 200W, then a replacement rig just got a lot cheaper! :-)