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I have the early Ella with the circuit board. I think its the M100. Can I change it over to use the all film capacitor power Supply? There are 2 47uf caps on the circuit brd.Are these part of the the power supply in this amp? If so I think the swap would be more difficult then just taking out the P.S. Brd, and replacing it with the new module. Anyone know about this older Ella amp. and how to do this? Thank You.
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My Ella is the same as the one in the photos above and I'm with Al (Tubegarden).
I replaced all the electrolytics in the B+ supply with polyprops. Those that didn't fit underneath are hanging out the back on top. Sounds great.
Yes that's the one. What I thought I would do is attach aluminum plates to the sides raising the amp up a couple of inches, and attaching a plate to the bottom of that. Essentially adding a basement to the housing. On this plate I thought I could mount the Power Supply, the Active Bias supply modules and the Film Caps to replace the 47uf caps on the board. However, like I said before, if the 47uf caps on the board are actually part of the power supply it would be more complicated to replace the power supply then if not. So are the 47uf electrolytic cap on the brd part of the power supply or not? Is this possible to do at all? I love my Ella, but would like to upgrade her some.
Tony G
Hi,
> What I thought I would do is attach aluminum plates to the
> sides raising the amp up a couple of inches, and attaching a
> plate to the bottom of that. Essentially adding a basement
> to the housing.
That would solve the space issues, but is a lot of work TBH.
A further alternative I just kind of remembered would be to place the power supply into an external case, like the border patrol power supply.
I did discuss some with Brian, but we did not really take this up so far.
One could use one of the larger project chassis with a pair of FCUPS and a pair of Tube rectifiers with a suitable canned transformer on top to power the original Ella chassis unmodified, the existing mains transformer would be left for the heaters only.
> On this plate I thought I could mount the Power Supply, the
> Active Bias supply modules and the Film Caps to replace the
> 47uf caps on the board.
Mounting stuff that connects to the top of the chassis on a removable bottom plate leads to a nightmare of wiring and assembly etc.
Better attach the ABS and FCUPS to the sides as shown here:
> However, like I said before, if the 47uf caps on the board are
> actually part of the power supply it would be more complicated
> to replace the power supply then if not.
These capacitors form the "supply line decoupling" for the Input and driver valves.
IF I where to work on the Amplifier I would likely get 4 pcs of the smallest mechanical size 450V or 630V 22uF capacitors (or 2 X 22uF & 2 X 10uF - the input tube is okay with 10uF) and place them besides the PCB. I would then create separate filter sections for left & right (they are currently combined) after cutting the necessary traces on the PCB.
I would add that dealing with these capacitors (and the six Wima's) alone without touching the main power supply will provide a major upgrade within the available space.
If you then elect to add my suggested 22Ohm/47uF Filter to each Channels high tension supply for the output stage you will get a large proportion of the benefits of the FCUPS within the existing chassis and would probably the most effective and easy upgrade.
The ABS PCB's are (by design) so small, you can normally easily find a place to put them. If you remove the bias pots you can place them directly in front of the power tubes, using stand-off's attached to the screws holding the tube sockets.
Ciao T
Hi,To be honest, I doubt this could be fitted, I seem to remember the old Opera sourced chassis where quite small inside.
We are talking about this?:
The FCUPS was designed to fit into the later, higher chassis with black anodised alu fronts and sides plus silver alu top panel, shown here from below:
It is too high in each orientation to fit the older chassis.
You could try to fit some big film capacitors into some of the remaining empty spaces in the chassis to connect them via a resistor after the original big power supply capacitors.
Using say 22 Ohm & 47uF would mean the film capacitor handles anything above 150Hz.
Adding a pair of 22uF capacitor to replace the capacitors on the M100 printed circuit board (obviously with long leads) would remove electrolytic capacitors from that part of the circuit.
A major upgrade can be had BTW replacing the three Wima coupling capacitors per channel (yes, three, not two) with higher quality capacitors, in case you have not done that.
Ciao T
Edits: 04/02/10
My old Ella has PP/Oil caps. They didn't fit anywhere, still don't. Also, the 50H chokes on each channel do not fit anywhere. Sounds wonderful, looks wretched ;)
Happy Ears!
Al Matcy
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