[Khorn]

Looking for an NOS 5AR4 rectifier tube that’s best compatible with my LS100 to replace the stock Sovtek tube. Any suggestions for improvements welcome.

[JackD]

Call Andy at Vintage Tube Services and see what he has in stock. The $70 Matsushita made in the Mullard tooled factory in Japan will get you about 95% to the Blackburn factory Mullards for about half to a third of the cost and will likely outlast you.  Though you can find them badged Matsushita most were made under OEM contract and branded as Dynaco, Westinghouse, Baldwin, etc. Trying to buy 5AR4's on Ebay could be an expensive waste of time. 

[Tyson]

I like the Japanese 5ar4's too.  The ones I have are labeled Toshiba and another set labeled Hitachi.  Both are excellent.  Of course I have NOS Mullards too and they are indeed the holy grail.  But for the $$ they go for nowadays, not worth it.  Japanese tubes from the 70's are really really good and actually quite close to the NOS Mullards.

I've also tried a bunch of new production 5AR4's and none of them are as good as the NOS stuff.  Which is too bad, because sometimes I do find new production tubes that are as good as NOS.  Just not this time.

[rbbert]

My experience with the Matsushita and UK Mullards mirrors Tyson's.  IMO it's hard to go wrong with it, especially if you get it through Andy.  It's sad how much prices for these NOS tubes have risen in the 4 years since I bought mine.

[Khorn]

I like the Japanese 5ar4's too.  The ones I have are labeled Toshiba and another set labeled Hitachi.  Both are excellent.  Of course I have NOS Mullards too and they are indeed the holy grail.  But for the $$ they go for nowadays, not worth it.  Japanese tubes from the 70's are really really good and actually quite close to the NOS Mullards.

I've also tried a bunch of new production 5AR4's and none of them are as good as the NOS stuff.  Which is too bad, because sometimes I do find new production tubes that are as good as NOS.  Just not this time.

Thanks,

Don’t care about the price. Just want best SQ and length of service for my particular preamp. BTW I’m in Canada. So far sounds fantastic and wonder what improvements over stock an NOS upgraded rectifier can offer.

[Zkidd]

I use an NOS 5V4 in my LS100 and I like it even better than the Mullard 5AR4. You can find great NOS 5V4 tubes for a third or even less that what you will pay for any NOS 5AR4. I believe Dan himself has received some emails from other LS100 owners who also sing the praises of the 5V4.

Just food for thought if you are looking at options and want to jump off the "ever increasing prices" train where NOS 5AR4 tubes are concerned. Since making the switch to the 5V4 I have never been tempted to put the Mullard back.

[jjss49]

uk mullard or dutch amperex 5ar4 (under various branding and labelling), or later japan made equivalent (made on mullard tooling) - conversation starts and ends with these

[Khorn]

Thanks all for the replies. It will be interesting to see what I end up with and what it brings to the table.  I’m overjoyed so far with the performance of this preamp. . Unexpectedly so.