Roberts Fans Look Away Now.

[Joe]

I first threatened this job a few weeks ago but was waiting for my breadboard to arrive so I could refine the amplifier design.

I was getting fed up of waiting for one thing and for another was actually wanting to use it so I got on with it yesterday.

I made a proper job of the case, in fact I was at it all afternoon, though the less said about the lettraset the better! This provided most of the interest and satisfaction and today I chucked a very crude amplifier together as a stop-gap.

I have taken Mark's advice about decoupling on board and that will be included in the proper version.

The R600 chassis is safe so this can easily be put back if it ever gets fixed. I was careful not to damage the case in anyway which is why the sockets are on the top even though this isn't really the best place for them.

       

[danny]

Hi iwas contenplating a similar project for a guitar practice/busking amplifier ! the roberts case looks good. not a rare set so i wouldnt worry to much if it doesnt get restored. Danny

[Joe]

That's what I thought and it's a nice-sounding speaker which it seemed a shame to to put to some use.

Have you checked out www.RunOffGroove.com for amp designs? It's worth a visit just to hear some of the samples.

Cheers
- Joe

[danny]

Hi just had a look at the web site yes there is some good little projects . I used to build Lm380 based amps when i was younger so am a dab hand at these type of chips. im planning on including effects in the amp. when i get fed up restoring tvs this will make a change for a day or so. Danny

[Mark Hennessy]

Looks good

And it's the earlier version of the R600 with the nicer (IMHO) grill. I have a feeling these might be rarer, so it's nice that you've kept that as original.

I hate doing Letraset too! Maplin used to sell a version that seems to last a lot better than the standard stuff - don't know if it's still available. These days, if I can, I use a computer to produce the text, printing it onto overhead transparencies. This works well behind Perspex front panels...

Mark

[Joe]

Strangely I prefer the newer Roberts grill - one of very few bits of 70s design that I do - but agree that this version is rarer so best not damaged. I recently got an RT-1 with a broken ferrite and have, so far, resisted robbing the R600 chassis to fix it. That set hasn't really been looked at yet as I've got a To Do heap developing and that too is the rarer 'Starry Night' case so deserves especial care

The day after I built, of rather threw together, the amp my breadboard arrived so I'll soon be doing some experiments on that to improve the design.

The big version is still in daily use for playing my DAB radio through and is also proving its worth as an external speaker when working on chassis without their own.

Cheers
- Joe

[fido]

I use a Brother electronic label printer. It does a neat job but the self adhesive labels have a white background rather than clear, which would be better.

[Joe]

I would have used my Dymo label thing but it's gone wrong and appears to be in a way I can't fix.

[Mark Hennessy]

Strangely I prefer the newer Roberts grill - one of very few bits of 70s design that I do - but agree that this version is rarer so best not damaged. I recently got an RT-1 with a broken ferrite and have, so far, resisted robbing the R600 chassis to fix it. That set hasn't really been looked at yet as I've got a To Do heap developing and that too is the rarer 'Starry Night' case so deserves especial care

Careful with those later grills - the black strips come off with hardly any provocation - even foam cleanser will soften the paint. If you like the look, check out the extruded aluminium grill on the 1970s Hacker Hunters et al, which is bombproof by comparison.

And congratulations on the RT1 - those are rather nice sets in any finish, but the specials are even nicer. I've repaired one or two in the past, so might be able to offer assistance

Oh, and talking of foam cleanser, it also removes the colour from the Rexine used by Roberts back then, so you'll need to find something milder. I don't know what - other than water(!) - foam cleanser is pretty harmless (or so I thought!)

Good luck, and sorry to go OT

Mark

[Brianc]

I recently got an RT-1 with a broken ferrite and have, so far, resisted robbing the R600 chassis to fix it.

The ferrite rod can be glued together with superglue with little or no effect on performance so don't rob the R600 chassis Joe.