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TUBES: Are these legit and safe for a DR103?

Posted: Thu Sep 13, 2012 3:54 am
by Kodou
I want to grab some tubes for my DR103 and have decided to go NOS so I don't have to mod my amp with the Bias circuit.

I have also been thinking of running it at 50w with two output tubes, mostly in order to save on tubes.

Would these be good for a vintage Hiwatt as far as durability goes?

http://www.ebay.com.au/itm/110938009523 ... 1423.l2649

I think for the price, it would mean I have 2 backup sets after I do the first retube.

Re: TUBES: Are these legit and safe for a DR103?

Posted: Thu Sep 13, 2012 10:17 am
by mhuss
It's not just NOS versus new, but rather the bias voltage versus idle current characteristic of the tubes. The old Hylights wre set up for original (NOS) Mullards. I have not tried Teslas, but I have had poor results with NOS Siemens and RFT tubes.

--mark

Re: TUBES: Are these legit and safe for a DR103?

Posted: Thu Sep 13, 2012 3:39 pm
by Dr.HI-TONE
if they are legit, they are supposed to be very good valves.
They look legit to me, but I am not really an expert.

Re: TUBES: Are these legit and safe for a DR103?

Posted: Thu Sep 13, 2012 3:54 pm
by mikhailwatt
mhuss wrote:I have not tried Teslas, but I have had poor results with NOS Siemens and RFT tubes.
I'm running a pair of "Black Eagle" Teslas (well, that's what Tubetramp calls 'em - no markings, rounded dome tops) in my '80 DR504.
Stock bias is spot-on, and they have a very nice breakup.

"YMMV"

Re: TUBES: Are these legit and safe for a DR103?

Posted: Fri Sep 14, 2012 4:30 am
by OldSchoolDave
Good tubes. You have to watch the TESLA date codes, though. They're kinda confusing and the later issues don't command the same respect.

I've bought tubes from a Lukas (a.k.a. LUC.key on another forum), from the Czech Republic, several times. If it is the same person, he's a straight shooter and locates some nice stuff. I just pm'd him and will let you know what I hear back.

Dave

Re: TUBES: Are these legit and safe for a DR103?

Posted: Fri Sep 14, 2012 4:04 pm
by OldSchoolDave
Update: This ebay seller is not the same person I've dealt with. Here are his comments about the auction:
trusted Czech Republic tube guy wrote:I've just checked the listing and it doesnt look bad, I would wonder about his testing though. I've learned my lesson about believing a tubetester values and rather check them in real amp. And those looks like typical tubetester values. They might be way off if it was tested on BM215A tubetester (common in here). Just my 2 cents
Dave