• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
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    the safety precautions around high voltages.

Ronette Info

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Can anybody tell me anything about this amplifer - anything eg:
Output power, sound quality, input sensitivity .....

Hope I do not get in trouble for publishing the circuit, is a 1957 model btw. :cannotbe:

Another guy (sadly died awhile ago - Ton Sistelan) was bussy rebuilding/designing it for todays use with CD player and using KT88 tubes. I bought the 90% complete amp for about 140 USD including new tubes. Got KT88 made by "Star" ?? and some gold pin Phillips EF86 and Miniwatt 18042 .

Obviously the specs will now be differant then the origenal, just asking for the matter of interrest.
 

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Probably around 35W output. The gain seems around 45 if i can read the resistor values properly. It was obviously designed to work with a piezo (crystal) pickup so 250mV seems about right.
Lots of NFB and unnecessary gain stages. An obvious upgrade would be to just convert it to a Dynaco St70.

Sound quality? Will largely depend upon the output iron.
Most sensible is to completely strip it down an reuse chasis, PS, outputs and (maybe) output valves. The PS is probably too high for anything class A.

Oops. Didn't notice it's pure pentode - lot's more power then. 60W?
 
Hi, I just wanted to ask how far Ton got adapting it for CD and if you intend using it for cd.
From the schematic it looks quite sensitive ( probably would have to be to suit piezo?)
Cd players on the other hand give typically from 1000 to 2000 mv, which is quite a bit. (Hope that was relevant)

The "Star" KT 88's I think are Chinese, I bought a pair off that very bloke (RIP) a few years back.
Cheers


Never play leapfrog with a unicorn
 
Dynsdale said:
Hi, I just wanted to ask how far Ton got adapting it for CD and if you intend using it for cd.

I actually completed it, just needed to connect all switches on the faceplate. Unfortunately, it did not work very well. Alot of big noise on the output. :scratch: I traced the circuit back to the drawings he made (adaptions), and could not find anything "wrong". He did add plenty of "gadgets" to the circuit like a complete pre-stage with phono inputs, tape rec. in/out, direct input, changes to the variable feedback functions and some other things. The rest of the circuit was like the origenal. Also the output transformers looks like if they where re-made, by hand?? :dodgy: The PSU was also not too well designed , only a CRCRC network - for the stereo system. Would thought a CLCRCRC would have been better for this setup.

I dismantlled it now and plan to rebuild it to this circuit:

Hashimoto KT88

What valve experience do you got and spares? May I contact you via e-mail?
 
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