Darkvoice 336i & 336SE Tuberolling PartII
Feb 19, 2020 at 5:11 AM Post #2,806 of 14,501
All of those listings are on the high side, imho, ESPECIALLY the first one, which I find easily $100 over priced. Do you need pairs? The Sylvania 6sn7w short bottle can be found around $100, the rca 'trending' at $21, and the tung sol around 40. It just takes some time and shopping around. Auctions often end up a lot less than the buy it now options, perhaps this one will end low:

https://www.ebay.com/itm/RCA-6AS7G-...573330?hash=item365d997a12:g:HnIAAOSwIqpeSaOA
Hi,

I do not need pairs, but I did not find single pieces from Top sellers.
I really want to avoid returns, and in all honesty, most of my past experiences with ebay were not that great ...
 
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Feb 19, 2020 at 7:30 PM Post #2,807 of 14,501
ebay (aka fleabay), just search "sylvania 6sn7" (without quotes). Go for 6SN7GT's and 6SN7GTA's. Ignore GTB's and flat plate GT's (just two flat plates with 5-7 holes each). The flat plate Sylvania 6SN7GT's (at least the ones I bought) are meh. As for test readings, they're not entirely accurate. My rule of thumb (as gleaned from these threads) is 15% above minimum, the higher the better of course.

As for power tubes, good budget starter ones are RCA 6AS7 (coke-bottles) and Tung-Sol 7236's.

EDIT: Adding an older post of mine (thanks @DenverW for the reminding me) if @SylvesterH wants a more clean, in-your-face type of sound from the DV336SE:

Speaking of 7236's, have you ever tried the Cetron (Richardson) versions? I have a pair but am waiting on an amp to hear them in. Tested very nicely on my Hickok, but unheard as of yet. There's a US seller on Ebay offering them for $25 each currently...just wondering if I should buy more now before they get scooped up (if they're any good).
 
Feb 27, 2020 at 8:04 PM Post #2,808 of 14,501
Speaking of 7236's, have you ever tried the Cetron (Richardson) versions? I have a pair but am waiting on an amp to hear them in. Tested very nicely on my Hickok, but unheard as of yet. There's a US seller on Ebay offering them for $25 each currently...just wondering if I should buy more now before they get scooped up (if they're any good).
Think most users here would agree that Tung Sol is the King of all 7236's, Anything else... well. Unless there's some raving reviews out there on the Cetrons.. (is there?) welll blow me waters down.... check this list out!!


THE LIST
I.a) GEC Curved Brown Base 6AS7G A1834 CV2523
I.b) Western Electric 421A
I.c) GEC Straight Brown Base 6AS7G A1834 CV2523

II.a.i) Tung Sol 5998
II.a.ii) Tung Sol 421A
II.a.iii) Cetron/Tung Sol 7236

http://the-key.enix.org/~krystal/review-tube-bottlehead.html

Is the Cetron made by Tung Sol?? Might be a GOOD BUY after all.. nice find @bcowen

https://www.ebay.com/itm/7236-vacuu...835508?hash=item2f39c773b4:g:WF0AAOSwDnpd2bqh
 
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Feb 27, 2020 at 8:52 PM Post #2,809 of 14,501
Think most users here would agree that Tung Sol is the King of all 7236's, Anything else... well. Unless there's some raving reviews out there on the Cetrons.. (is there?) welll blow me waters down.... check this list out!!


THE LIST
I.a) GEC Curved Brown Base 6AS7G A1834 CV2523
I.b) Western Electric 421A
I.c) GEC Straight Brown Base 6AS7G A1834 CV2523

II.a.i) Tung Sol 5998
II.a.ii) Tung Sol 421A
II.a.iii) Cetron/Tung Sol 7236

http://the-key.enix.org/~krystal/review-tube-bottlehead.html

Is the Cetron made by Tung Sol?? Might be a GOOD BUY after all.. nice find @bcowen

https://www.ebay.com/itm/7236-vacuu...835508?hash=item2f39c773b4:g:WF0AAOSwDnpd2bqh

I have not done any thorough research on the Cetrons, but what I do know is they were a Richardson Electronics brand (National being another). Richardson never manufactured receiving tubes, just distributed them. I believe Cetron and National were simply OEM brands made for them by others with those brand labels. I've read in a couple places that the 7236's were made by TungSol which may be true, but I haven't run across anything yet that's convincing or definitive. I had some Cetron 300B's a while back that were quite good. Not to the level of a Western Electric, but way cheaper and way better than stuff coming out of China at the time (1990's). Have no clue who actually made them though.

Still haven't had the opportunity to hear these (waiting on amp), but I went ahead and bought a few more just in case they're good. Most of the online dealers are asking $75 and up for these, so the $25 on Ebay is a steal....unless they suck. :)
 
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Feb 27, 2020 at 9:24 PM Post #2,810 of 14,501
At that price I would try them for sure. I will say, however, that I completely disagree with the placement of the 7236 on that list. I was not impressed at all with the 7236, and found them a minimal upgrade over the tung sol 6080. Perhaps not even an upgrade at all. I was much higher on the tung sol 6as7g, and feel like it should be ranked higher. It’s all subjective, though.

ive yet to hear a gec 6as7g round base, though I have a straight base and a WE 421a. The 421a made a major improvement in sound quality to any other power tube I tried, and is my current favorite. Hunt eBay, as you can find 421a for not death prices once in a blue moon.
 
Feb 27, 2020 at 9:31 PM Post #2,811 of 14,501
TungSol 7236:
1582856709068.png


Cetron 7236:
1582856760618.png


Hard to tell for sure from the different picture angles, but they look pretty similar. As luck would have it the TungSol pictured above is from a just listed Ebay ad for $27. So of course I bought it (for the good of the community and all) and can compare them in the flesh here shortly. :)
 
Feb 27, 2020 at 9:36 PM Post #2,812 of 14,501
TungSol 7236:
1582856709068.png

Cetron 7236:
1582856760618.png

Hard to tell for sure from the different picture angles, but they look pretty similar. As luck would have it the TungSol pictured above is from a just listed Ebay ad for $27. So of course I bought it (for the good of the community and all) and can compare them in the flesh here shortly. :)
Please do!! Looking forward to this.. :)
 
Feb 27, 2020 at 9:41 PM Post #2,813 of 14,501
At that price I would try them for sure. I will say, however, that I completely disagree with the placement of the 7236 on that list. I was not impressed at all with the 7236, and found them a minimal upgrade over the tung sol 6080. Perhaps not even an upgrade at all. I was much higher on the tung sol 6as7g, and feel like it should be ranked higher. It’s all subjective, though.

ive yet to hear a gec 6as7g round base, though I have a straight base and a WE 421a. The 421a made a major improvement in sound quality to any other power tube I tried, and is my current favorite. Hunt eBay, as you can find 421a for not death prices once in a blue moon.

I've been keeping my eyes peeled for a WE 421A, but haven't found one that I like yet. Seems the ~$200 range ones are either untested and sold with no returns or have dubious test scores. The ones that appear to be genuinely NOS with some credible info to support them are $300+. I was cracking up watching the last minute bidding on one that was advertised as untested, as-is, no returns, etc. The getter flash was almost completely gone at the bottom save for one small area that was quite obviously white. Vacuum be gone. It ended up selling for $150. Amazing.

But I'll score one of these days...hopefully. :)
 
Feb 27, 2020 at 10:01 PM Post #2,814 of 14,501
I got some from a guy on eBay named smtelco. 100 positive feedback, selling new in original box. auction bids, under 200.

First one had a dead channel out of the box. Wrote him and he was nice about it, sent me another tube. The new one failed painfully (thought it blew out my headphones) in the right channel in under a week with light to little use. Wrote him again, and he was much less understanding. I sent both tubes back to him, and requested a refund. He suddenly stopped communicating and I had to get a refund via PayPal. It’s hit or miss on eBay, but overall at least there is some protection for buyers.
 
Feb 27, 2020 at 10:41 PM Post #2,815 of 14,501
TungSol 7236:
1582856709068.png

Cetron 7236:
1582856760618.png

Hard to tell for sure from the different picture angles, but they look pretty similar. As luck would have it the TungSol pictured above is from a just listed Ebay ad for $27. So of course I bought it (for the good of the community and all) and can compare them in the flesh here shortly. :)

Looking forward to the comparison too...

When Cetron 7236 was in production, Tung Sol 7236 had been gone for long time, I remember Tung Sol had been sold twice before Cetron got it. The two 7236s do have some differences: Tung Sol has higher base, Tung Sol has thicker top getter flash where you can barely see the top mica and getters (whereas in Cetron you can see the top mica and getters clearly), Tung Sol has square top getters vs Cetron has circular top getter. I hope the difference is not as big as GT vs GTB.
 
Feb 27, 2020 at 10:55 PM Post #2,816 of 14,501
I got some from a guy on eBay named smtelco. 100 positive feedback, selling new in original box. auction bids, under 200.

First one had a dead channel out of the box. Wrote him and he was nice about it, sent me another tube. The new one failed painfully (thought it blew out my headphones) in the right channel in under a week with light to little use. Wrote him again, and he was much less understanding. I sent both tubes back to him, and requested a refund. He suddenly stopped communicating and I had to get a refund via PayPal. It’s hit or miss on eBay, but overall at least there is some protection for buyers.

Feel sorry for your bad experience with 421A. I think Paypal should be able to hold the seller accountable and refund you.

So sad that it's risky to buy 5998 / 421A tubes, especially given their astronomical prices. I read earlier that 5998 is prone to arcing - at least 2 HF fellows had their headphones destroyed by 5998 arcing. I thought 421A might be better than 5998, but then you also had arcing in 421A. Well, 421A is basically a cherry-picked 5998, so I shouldn't be surprised to read arcing in 421A.
 
Feb 27, 2020 at 11:01 PM Post #2,817 of 14,501
You were lucky...at least your headphones/eardrums were not blown by the arcing.

Tube arcing is really terrible.

SO when trying new tubes, must use sacrificable cans, and must plug in the cans long after the tubes are heated up.
 
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Feb 27, 2020 at 11:07 PM Post #2,818 of 14,501
Thanks! I did end up getting a refund, but I had to jump through some hoops, such as providing proof of return shipping. The guy no longer has perfect feedback :).

The arcing is one of the reasons i've slowed down a LOT on my tube rolling varieties. It might be completely unfounded, but I feel like the 421a and 5998 are more fussy with input tubes, where as the 6as7 just about takes anything. If I didnt love the sound on the 421a so much I'd just use the GEC 6as7g only. One day i'll either trade into or find a reasonable round base 6as7g and my power tube rolling days will be over :).
 
Feb 28, 2020 at 9:27 AM Post #2,819 of 14,501
Feel sorry for your bad experience with 421A. I think Paypal should be able to hold the seller accountable and refund you.

So sad that it's risky to buy 5998 / 421A tubes, especially given their astronomical prices. I read earlier that 5998 is prone to arcing - at least 2 HF fellows had their headphones destroyed by 5998 arcing. I thought 421A might be better than 5998, but then you also had arcing in 421A. Well, 421A is basically a cherry-picked 5998, so I shouldn't be surprised to read arcing in 421A.

The 421A was a designation exclusive to Western Electric, wasn't it?
 
Feb 28, 2020 at 10:20 AM Post #2,820 of 14,501
To my limited knowledge the 421a was made by western electric, and has small Differences from the 5998.
 

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