30-08-2015, 09:48 PM
This is indeed a wonderful amplifier hiding in a big Dnsette cabinet and there is a lot more than can be seen on the surface.
Even the aluminum grills are in immaculate condition.
The output stages are almost exactly the same as the Mullard 5-20 but that is where the basics end.
Under the chassis it gets much more interesting there being a further three valves.
From the volume control going back there is an ECC83 active tone control with line in and ceramic gram in switched to it.
Then for the three more sensitive inputs there is a further two EF86s with switchable equalization for none (dynamic microphone) and (RIAA for magnetic gram) and after all that (NAB tape head).
Perhaps we have a Mullard 8-20 circuit if ever there was such a thing. Certainly we have a high end amplifier here for all to see.
All of these preamp stages along with the rectifiers have there numbers printed in snake oil yellow and I bet it will not make any difference to how good it is going to sound.
If you have a preamp for sale this one is no sale as it is all built in
Restoration is going to be pretty easy for the output stages with all components having easy access.
This is not so for the preamp stages as all the coupling capacitors are caged under the equalization components and is going to make it a little bit more of a challenge to do.
Those output connectors on the power supply sure have sharp teeth with 400V on the pins. Keep your fingers out
We have also got a date of 1955 on one of the capacitors in each channel so late 1950s it is.
We also have a makers name for the transformers.
Last but not least there is a resistor and capacitor that has been hastily linked out some time ago. This has the little fan connected across it. The reason for this being linked out is that it is in the negative HT between the reservoir and smoothing capacitors. How horrid could anything be. A DC motor effectively in series with the HT
I have had a bit of a slow start and will leave the reason for it to another thread in the news section.
Even the aluminum grills are in immaculate condition.
The output stages are almost exactly the same as the Mullard 5-20 but that is where the basics end.
Under the chassis it gets much more interesting there being a further three valves.
From the volume control going back there is an ECC83 active tone control with line in and ceramic gram in switched to it.
Then for the three more sensitive inputs there is a further two EF86s with switchable equalization for none (dynamic microphone) and (RIAA for magnetic gram) and after all that (NAB tape head).
Perhaps we have a Mullard 8-20 circuit if ever there was such a thing. Certainly we have a high end amplifier here for all to see.
All of these preamp stages along with the rectifiers have there numbers printed in snake oil yellow and I bet it will not make any difference to how good it is going to sound.
If you have a preamp for sale this one is no sale as it is all built in
Restoration is going to be pretty easy for the output stages with all components having easy access.
This is not so for the preamp stages as all the coupling capacitors are caged under the equalization components and is going to make it a little bit more of a challenge to do.
Those output connectors on the power supply sure have sharp teeth with 400V on the pins. Keep your fingers out
We have also got a date of 1955 on one of the capacitors in each channel so late 1950s it is.
We also have a makers name for the transformers.
Last but not least there is a resistor and capacitor that has been hastily linked out some time ago. This has the little fan connected across it. The reason for this being linked out is that it is in the negative HT between the reservoir and smoothing capacitors. How horrid could anything be. A DC motor effectively in series with the HT
I have had a bit of a slow start and will leave the reason for it to another thread in the news section.
