Real Reissue KT66's

Tim Hall · 11-10-2007, 10:22 PM

I'm getting so tired of reading the hyped puke manufacturers and distributors write about their tubes.

Does anyone know if any of the current-stock KT66's out there are truly based on the original Genalex design, and not just a repackaged 6L6? I'm assuming any tube that has the amazing ability to be 100% compatible in any 6L6 amp with a draw of 0.9ma is just a rebottled 6L6.

I'm also open to any completely subjective opinions about these tubes...as long as it's not the manufacturer's blurbs being regurgitated

Tim

Old Tele man · 11-11-2007, 12:03 AM

...short answer is "no," just some are LESS far from the original specs than others.

MWJB · 11-12-2007, 09:44 AM

As Old Tele Man infers, it's probably a bit optimistic to expect any tube made in a different factory, in a different country, decades after the original to sound EXACTLY like the "real" thing. But AFAIK it is only the new Sovtek/New Sensor/Tung Sol KT66 (6L6 in a big bottle) that claims to be a "drop in" replacement, the JJ, TAD & Harma/GTKT66HP (Reflector) all draw 1.3A of heater current.

I've had good experiences with the Harma/GTKT66HP (they sound like a KT66, rather than a 6L6 - smooth, round, relaxed hi end). I have a JJ KT66 in my Champ at the minute, but as availability is intermittent (round here at least) for the GT/Harma, I haven't had the chance to compare directly. I am not rich enough to compare directly with a GEC but check out the Watford Valves 6L6 test report from 2005.

stokes · 11-14-2007, 12:43 AM

I have a set of original GEC KT66's in one of my amps,and have compared the Sovtek and Tung-Sol's and they dont come close.

Tim Hall · 11-14-2007, 02:53 PM

Thanks for the replies guys. I did a little more research on my own. Of course there are no real KT66's being produced any more, but I had a short exchange from Doug at Doug's tubes, and it seems the Chinese tubes are probably the closest current-production thing out there. I've heard the GT's are pretty good too.

Doug also has some Russians out of the Saratov plant that are supposed to be darn close. I think pretty much everything else out there is a 6L6. I think the JJ's are probably closer to a 6L6.

MWJB · 11-14-2007, 03:02 PM

The GT and Harma tubes are from the Saratov (Reflector) factory in Russia. This is the same factory that makes the Sovtek/Tung Sol KT66, but the GTHP & Harma are only availble via GT & Watford Valves.

The JJ is relatively new.

If the GTHP/Harma sounds "pretty darn close" and the Chinese tube is "closest current production" why isn't it "real"? I doubt that it would be identical wherever it was made.

Undoubtedly the GECs are the thing to have but NOS prices are not realistic for your average musician.

Tim Hall · 11-14-2007, 05:45 PM

Yeah Doug has some GEC's for sale too. At $100 a pop and four sockets to fill, I think I'll go with the copies.

stokes · 11-15-2007, 02:23 AM

And the ones Doug has are used.Imagine finding 4 that are matched.I got lucky and found a NOS pair of GEC's at a flea market for $100-I'm sure it'll be the last pair that amp sees.They are way out of control,$400+ a pair,and I've seen people pay $300 for a single on ebay.

Jammin'John · 12-06-2007, 02:15 AM

I'm runnin' a pair of those chinese {shuguang} ones in a Low Power Tweed Twin.

They sound and look nice.

JJ

clyde1 · 12-20-2007, 03:49 PM

I'm running a pair of Shuguang KT66's in a JTM45 I built for a customer and we're getting 500vdc on the high side of a low-high switchable B+ arrangement and I'm a little nervous about these tubes even though I have 1K
screen resistors right off the rail. The original had a 1K common resistor and a 470R for each screen. Does anyone know the plate and screen voltage ratings for these babies?

Jammin'John · 12-20-2007, 03:56 PM

These tubes are 25w tubes.

They won't take what a modern 6L6 (30w) tube will take.

I'm running them in cathode bias at 400v/40ma.

JJ

11-10-2007, 10:22 PM	#1
Tim Hall Member Join Date: Apr 2007 Location: Texas Posts: 71	Real Reissue KT66's I'm getting so tired of reading the hyped puke manufacturers and distributors write about their tubes. Does anyone know if any of the current-stock KT66's out there are truly based on the original Genalex design, and not just a repackaged 6L6? I'm assuming any tube that has the amazing ability to be 100% compatible in any 6L6 amp with a draw of 0.9ma is just a rebottled 6L6. I'm also open to any completely subjective opinions about these tubes...as long as it's not the manufacturer's blurbs being regurgitated Tim

11-11-2007, 12:03 AM	#2
Old Tele man Senior Member Join Date: Oct 2007 Location: Tucson, AZ Posts: 431	...short answer is "no," just some are LESS far from the original specs than others. __________________ ...and the Devil said: "...yes, but it's a DRY* heat!"* Last edited by Old Tele man; 11-11-2007 at 02:08 AM.

12-06-2007, 02:15 AM	#9
Jammin'John Member Join Date: Jun 2006 Posts: 89	Low Power Twin I'm runnin' a pair of those chinese {shuguang} ones in a Low Power Tweed Twin. They sound and look nice. JJ

12-20-2007, 03:49 PM	#10
clyde1 Member Join Date: Jul 2006 Posts: 82	Ratings? I'm running a pair of Shuguang KT66's in a JTM45 I built for a customer and we're getting 500vdc on the high side of a low-high switchable B+ arrangement and I'm a little nervous about these tubes even though I have 1K screen resistors right off the rail. The original had a 1K common resistor and a 470R for each screen. Does anyone know the plate and screen voltage ratings for these babies?

12-20-2007, 03:56 PM	#11
Jammin'John Member Join Date: Jun 2006 Posts: 89	Too Much These tubes are 25w tubes. They won't take what a modern 6L6 (30w) tube will take. I'm running them in cathode bias at 400v/40ma. JJ

11-12-2007, 09:44 AM	#3
MWJB Old Timer Join Date: Jun 2006 Posts: 1,926	As Old Tele Man infers, it's probably a bit optimistic to expect any tube made in a different factory, in a different country, decades after the original to sound EXACTLY like the "real" thing. But AFAIK it is only the new Sovtek/New Sensor/Tung Sol KT66 (6L6 in a big bottle) that claims to be a "drop in" replacement, the JJ, TAD & Harma/GTKT66HP (Reflector) all draw 1.3A of heater current. I've had good experiences with the Harma/GTKT66HP (they sound like a KT66, rather than a 6L6 - smooth, round, relaxed hi end). I have a JJ KT66 in my Champ at the minute, but as availability is intermittent (round here at least) for the GT/Harma, I haven't had the chance to compare directly. I am not rich enough to compare directly with a GEC but check out the Watford Valves 6L6 test report from 2005.

11-14-2007, 12:43 AM	#4
stokes Old Timer Join Date: May 2006 Location: NYC Posts: 1,306	I have a set of original GEC KT66's in one of my amps,and have compared the Sovtek and Tung-Sol's and they dont come close.

11-14-2007, 02:53 PM	#5
Tim Hall Member Join Date: Apr 2007 Location: Texas Posts: 71	Thanks for the replies guys. I did a little more research on my own. Of course there are no real KT66's being produced any more, but I had a short exchange from Doug at Doug's tubes, and it seems the Chinese tubes are probably the closest current-production thing out there. I've heard the GT's are pretty good too. Doug also has some Russians out of the Saratov plant that are supposed to be darn close. I think pretty much everything else out there is a 6L6. I think the JJ's are probably closer to a 6L6.

11-14-2007, 03:02 PM	#6
MWJB Old Timer Join Date: Jun 2006 Posts: 1,926	The GT and Harma tubes are from the Saratov (Reflector) factory in Russia. This is the same factory that makes the Sovtek/Tung Sol KT66, but the GTHP & Harma are only availble via GT & Watford Valves. The JJ is relatively new. If the GTHP/Harma sounds "pretty darn close" and the Chinese tube is "closest current production" why isn't it "real"? I doubt that it would be identical wherever it was made. Undoubtedly the GECs are the thing to have but NOS prices are not realistic for your average musician.

11-14-2007, 05:45 PM	#7
Tim Hall Member Join Date: Apr 2007 Location: Texas Posts: 71	Yeah Doug has some GEC's for sale too. At $100 a pop and four sockets to fill, I think I'll go with the copies.

11-15-2007, 02:23 AM	#8
stokes Old Timer Join Date: May 2006 Location: NYC Posts: 1,306	And the ones Doug has are used.Imagine finding 4 that are matched.I got lucky and found a NOS pair of GEC's at a flea market for $100-I'm sure it'll be the last pair that amp sees.They are way out of control,$400+ a pair,and I've seen people pay $300 for a single on ebay.

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