2. amps-preamps
  3. 140531-42455

Rectifier Tube Rolling in a Modwight LS 36.5DM

I was hoping to get advice, I have been rolling Rectifier tubes in my two box preamp I am blown away how different tubes change the sound ,I own two sets of Mullard GZ37/CV378 a set of GE 5U4GB both vintage early 1960's and a set of stock Sovtek 5AR4 also have a NOS set of 6H30 DR I am trying in the clean  box , both the Mullard's and Dr tubes only have about  five hours of run in time but the sound seems defused on the top end ok on the bass the GE Tubes are good in the mids but soft on the highs and bass so far the stock Sovtek seems to sound best ,Dan says try 5R4-GY Tubes, any one tell me about  the Mullard's in this preamp I am getting frustrated,  thanks 
goofy
roberjerman
4,319 posts
 
Tube brands DO NOT have distinctive tonal qualities! The "golden ear" crowd can throw stones at me! For the record, I have been around tubes and tube gear from young (the Fifties)!
roberjerman
4,319 posts
 
I have tried to give the OP some practical advice - and maybe save him from disaster! 
facten
2,938 posts
 
@robergerman
" If you desire a "different" sound you can try different makes of the other tubes in your preamp: 12A*7/ECC81,82, 83's/5751's, 7025's, 6DJ8/6922/ECC88's, 6SL/6SN7's ..  This is a SAFE method!"
Not sure what you are telling him as his preamp doesn't take these other tubes.
" Tube brands DO NOT have distinctive tonal qualities"

So, all tube brands sound alike? Not sure what you have been listening to.


facten
2,938 posts
 
goffy
I use a NOS Philips 5AR4 rectifier in my Modwright LS100 preamp , and a NOS Mullard 5AR4 rectifier in my Modwright Elysee DAC , haven't had any sound "anomalies" using either; and found both to be better than the stock new production rectifiers
flapjack
116 posts
 
Not sure about sound differences but I've seen new Russian versions create fireworks when replacing an original tube of the same specs.
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