Quicksilver mono block 8417's modified

ask your general tube related questions here

Quicksilver mono block 8417's modified

Postby burnedfingers » Tue Dec 20, 2011 5:59 am

I don't know if there is a following here of people that own 8417 mono block amps but if there is I can share some info.

I have owned 4 sets of these 8417 mono blocks plus a set of KT88 mono block amps. There is no need to scrounge and pay big bucks for those expensive 8417 tubes. A slight modification of the bias circuit will allow the owner to use 6L6GC's, EL34's,KT88's,KT90's, 6550's, 6n3cE's, and 6bg6GA's.

Remove the 1/4 bias jack and normal thru the transformer CT's to ground.
Mount a 50K pot in its place. Install a 10 ohm resistor from the cathode to ground each output tube. The rest is a no brainer just parallel the pot wiring and install a 1k resistor from the input and ground leg of the pot nearest the bias circuit.

Its NOT necessary to parallel the VA tube sections or the phase inverter sections in order to run tubes other than the 8417 like mentioned in an article on 8417 conversion.

Jumper pin 8 to pin 1 on the output tube socket and this will allow one to use EL34's.
burnedfingers
KT88
 
Posts: 640
Joined: Mon Sep 05, 2005 6:38 am

Return to tube 101

Who is online

Users browsing this forum: No registered users and 11 guests

cron