Oil the fan while you are in there.
Clean the ground contact point.
Tighten the speaker terminals if needed.
May want to replace relay, those are the contact points
that the single passes thru.
Re grease the TO3 output transistors, and clean the contacts while you are doing this.
New bridge rectifier soft recovery type.
Bypass the big caps with 5uf poly pro or oil.
(make sure they are not leaking and are still good probably are but just check around the screw terminals)
The internal wire change will not make that much difference sonically.The power cord will, esp if you can
fit a 20 amp IEC in there.
Bypass the input coupling capacitor, if your pre already has an output cap.
Change out the electic caps on each driver board
Cerafines or equivalent.
Put volt regulation on the pre driver stage, do not do it
on the driver stage it restricts the sound.
Change the driver tranistors from bypolar to mosfets
and put low capacitance bypolars inplace of the old predriver tranistors.
If you want a DH500 already done to this level email me
I have afew done already.
Clean the ground contact point.
Tighten the speaker terminals if needed.
May want to replace relay, those are the contact points
that the single passes thru.
Re grease the TO3 output transistors, and clean the contacts while you are doing this.
New bridge rectifier soft recovery type.
Bypass the big caps with 5uf poly pro or oil.
(make sure they are not leaking and are still good probably are but just check around the screw terminals)
The internal wire change will not make that much difference sonically.The power cord will, esp if you can
fit a 20 amp IEC in there.
Bypass the input coupling capacitor, if your pre already has an output cap.
Change out the electic caps on each driver board
Cerafines or equivalent.
Put volt regulation on the pre driver stage, do not do it
on the driver stage it restricts the sound.
Change the driver tranistors from bypolar to mosfets
and put low capacitance bypolars inplace of the old predriver tranistors.
If you want a DH500 already done to this level email me
I have afew done already.