Any Moto heads? Need OT advice please

[oldtexasdog]

I have a Motorola HS-711B console (16w)(4-EL84's and 12AXTx2 with a 5U4G) I got with no output transformers? I'm going to re-cap and do a full resistor R&R and make it a stand alone. It has a huge PT. The orginal OT's were from the schematics 5500 Ohm input and 6-8 ohm out.
I thought I might get a better FQ responce and sound by taking the coulping caps up from .02MFD to say 1.5 or .22 and putting in a pair of new OT's-These are the two I am looking at-suggestions?
25w
input-7.6K ohm
Out-8-ohm
20-20K Hz responce
Screen/grid-40%

OR
60w
input 10K ohm -it would lower the gain by about 1dB
out-8 ohm
20-20K
S/G-40%

I also thought about doing a UL Mod by going to pin 6 on the EL84's with a in-line 100 Ohm 2w resistor from the OT's?

Your thought are appreciated and I would inc the schematics but I get a "File size to large".

 

[DF96]

I assume this has no NFB, or you understand and have modelled the LF stability effects of a change in OPT and coupling capacitors? 'UL Mod' probably requires more than adding a resistor.

 

[oldtexasdog]

Thanks
It does have NFB-I think I will go with some 12AT7's instead of the 12AX7's and go Ul using a pair of OT's with these specs then
15w
10K input
6 ohms out
40% s/g
40-18k Hz
?

 

[DigitalJunkie]

Also,I'd be careful about your proposed coupling cap values. I'd start with double the 'stock' value(0.047uf),and go from there. Beware that too large of a value may cause LF stability problems,.22 might be a bit on the large side. 1.5uf would be insanely huge,and is likely to cause problems,IMO.

 

[oldtexasdog]

Thank you!