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Old Yesterday, 01:26 PM   #1
snaarman is offline snaarman  United Kingdom
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Default Next: Guitar combo in a Dansette?

So, next project will be a small valve amp in a 60's record player. I am getting a broken Bush valve record player (rather like the popular UK brand Dansette, but cheaper to buy). It will need some modifications to sound good.

Look away now if you are of a nervous disposition.

I plan to remove the autochanger deck and all inner woodwork, cut the lid and fit a 10 inch Celestion and re-use the original controls for volume and tone.

You carry the amp by the side handle on stage like you brought your old record player, but you stand it up with the controls at the top and the lid/speaker facing forwards.

The existing chassis has two B9A sockets so it could be 12AX7 and EL84 perhaps. This thing dates back to the "live chassis" era - so I can't re-use the mains transformer 'cos there ain't one.

Ah, those were the days

Pete
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Old Yesterday, 02:07 PM   #2
Kay Pirinha is offline Kay Pirinha  Germany
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Fascinating idea! I think there'll be enough space to add a 35 to 50 VA mains transformer plus silicon bridge.
Best regards!
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Old Yesterday, 02:12 PM   #3
Galu is offline Galu  Scotland
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Let's not 'Beat about the Bush' - this project sounds like fun!
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Old Yesterday, 02:28 PM   #4
snaarman is offline snaarman  United Kingdom
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Quote:
Originally Posted by Galu View Post
Let's not 'Beat about the Bush' - this project sounds like fun!
He he..

There's a sneaky trick I have planned. You remove the horrible elliptical speaker and the hole acts as a cabinet port.

Then you reverse the way the lid opens by moving the hinges from the back to the front. Now you can partly open the "record player" to increase the inner volume and also point the speaker slightly upwards. Some woodwork issues to consider but I think that is worth trying.
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Old Yesterday, 02:29 PM   #5
snaarman is offline snaarman  United Kingdom
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Quote:
Originally Posted by Kay Pirinha View Post
Fascinating idea! I think there'll be enough space to add a 35 to 50 VA mains transformer plus silicon bridge.
Best regards!
Yes, exactly. I am still considering where the power switch goes. The original design has it as part of the bass control but I don't want to bring mains power that close to the tone stack....
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Old Yesterday, 02:31 PM   #6
JMFahey is offline JMFahey  Argentina
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Maybe you don´t even need to cut much woodwork, if at all.
Start by removing the record changer and show what´s inside.
Will you keep the original 1 to 2W power level (meaning you can use the original OT) or add full PT and OT complement?

A single EL84 + 12AX7 let you make a tasty VOX AC4 clone ; or if using a couple ECL82 you have 2 pentodes, 2 triodes which can provide up to twice the power with the same number of bottles.

Not much power in any case so choose a nasty biting speaker to cut through the stage mud, such as a Celestion G 10 25 or whatever they call it now (whatever the old Marshall Lead 12 used) or Jensen MOD10-35 or similar.

A heavier bassier speaker like Celestion Tube 10 or similar needs more power than you´ll have available and in any case you already forfeited powerful Bass by choice of enclosure, something chimey will use it better.

But please show what´s inside
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Old Yesterday, 02:32 PM   #7
JonSnell Electronic is offline JonSnell Electronic  United Kingdom
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This model, as in the Dansette range, uses the motor with a tap for the heaters.
Why not fit a small horn, similar to a Leslie Cab, running off the motor.
You will need isolation from the mains of course, as you have already mentioned.
As all venues nowadays have a house PA, mic up the speaker and you won't need any more extra power.
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Old Yesterday, 02:47 PM   #8
snaarman is offline snaarman  United Kingdom
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Let's type that all again shall we..

I like the idea of using the turntable as a Leslie. I wonder if that has been done before.. However I need the internal space to fit the Celestion 10-30 speaker I have for this project.

Likewise I can't use the valves as they are series heater types run off that motor tap (brilliant corner cutting by some sixties engineer). So it's either a single EL90 or EL84 and 3 to 5 watts, which I know is just about enough even if you are next to the drum kit in a small gig.

Last edited by snaarman; Yesterday at 02:51 PM.
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Old Yesterday, 02:52 PM   #9
JonSnell Electronic is offline JonSnell Electronic  United Kingdom
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I would use an ECL86, similar power output and a pre amp in the triode.
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Old Yesterday, 03:57 PM   #10
Kay Pirinha is offline Kay Pirinha  Germany
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...but scarce and hence ultra expensive !
By economical reasons I'd prefer two ECL82's, as yet suggested. Roughly representing half a 6SL7, this tube's triode isn't that bad at all.
Or you go for series heated tubes (PCL86, PCL82, UCL82, whatever you want), get an isolation tranny as the PT, tie the heaters in series and drop the superfluous heater voltage over a suitable capacitor.
Best regards!
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Last edited by Kay Pirinha; Yesterday at 04:07 PM.
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