New Tube Alert***********

[Roccaforte Amps]

I'm done testing my batch of the new TungSol 5881
re-creation. Its good, and guess what?
It actually has the identical plate structure.
Not a rebranded tube, finally.

 

[KLB]

Cool, Doug.

What plate load range do you think this tube will be "happiest" with, 6.6K/7K or 4K/5K?

How many volts are the plates and screens rated at?

How many watts can we realistically expect from a pair?

Thanks for the heads up!

- Ken

 

[Roccaforte Amps]

Originally posted by KLB
Cool, Doug.

What plate load range do you think this tube will be "happiest" with, 6.6K/7K or 4K/5K?

How many volts are the plates and screens rated at?

How many watts can we realistically expect from a pair?

Thanks for the heads up!

- Ken

I ran a quad at 450V 50ma all day, and also tested this amp at full tilt, the tubes never coughed. I'd at the least expect them to handle anything the original can withstand. The plate structure is identical, and as with most Russian made output tubes, they usually go farther than the old stuff could.
SED EL34's anyone?

 

[tube tramp]

might i inquire how much these fine tubes are costing ...has anyone a b tested these against the real ones? . i do hope they are not like the other versions, and remakes that new sensor is responsible for.thank you tt

 

[Roccaforte Amps]

Originally posted by tube tramp
might i inquire how much these fine tubes are costing ...has anyone a b tested these against the real ones? . i do hope they are not like the other versions, and remakes that new sensor is responsible for.thank you tt

Yes, I AB'd them to originals, excellent job they did on these.
New Sensor has these listed in their catalog around the 20.00USD range, but expect to probably pay a little more.
I just wrote an article detailing the test results for my mag.
Heres a picture of the old and new, note the plate:

 

[tube tramp]

they certainly pass the visual even with crazy ivan on it. hmm wonder if my units would slay em at 485 like they did all the other subjects ive tried. once in a while ive noticed that some of the replica tubes work pretty well.anything would be a treat that was improving. because in lieu of the mullards they make and gts feeble effort.makes ya kinda wonder what got left out of the recipes. as we know for a fact that most of the materials used to make the old tubes came from every corner of the planet.givin todays bean counting methods .but with modern technology in mind.i will try some.thanks ...i take it that the russians have the original tooling for this .tt

 

[Killa-B]

I wouldn't have tried these before, but now old Doug has got me thinking.

It the old Tung Sol tube was 100, what would these tubes rate with reliability not taken into account? Tone performance only, just your take Doug.

 

[Leftee]

This is pretty cool news!

 

[riffmeister]

God, I love the originals.....a better output tube for my TopHat Super Deluxe does not exist.

The new one looks cheezy.

 

[rastaman]

Thanks for the info Doug!

 

[Laroosco!]

Originally posted by riffmeister

The new one looks cheezy.

 

[BozoTone]

AAAaaahhhhh, Fester climbs though the window....good to see ya...we need to talk about a few sets of those fine Telam 84's...loved the original TS 5881's and anxious to hear the new take....nothing finer in a Tweed Bassman.....

 

[Roccaforte Amps]

Originally posted by Killa-B
I wouldn't have tried these before, but now old Doug has got me thinking.

It the old Tung Sol tube was 100, what would these tubes rate with reliability not taken into account? Tone performance only, just your take Doug.

These are good tubes, try them and see.
I'm for once very satisfied with the results
coming from a re-creation. This is a first.
I have a more technical article with test
results in my mag. The info will be up there
later today. Doug

 

[Roccaforte Amps]

Originally posted by BozoTone
AAAaaahhhhh, Fester climbs though the window....good to see ya...we need to talk about a few sets of those fine Telam 84's...loved the original TS 5881's and anxious to hear the new take....nothing finer in a Tweed Bassman.....

You looking for Telam EL84's?
How many you want, I'm loaded.

 

[Roccaforte Amps]

Originally posted by riffmeister
God, I love the originals.....a better output tube for my TopHat Super Deluxe does not exist.

The new one looks cheezy.

Looks cheezy? Its damn near exact. You try them and see what you think, I'm impressed, and I stock hundreds of the originals.

 

[Kiwi]

A dumb Q, for Doug and others ... I have zero tech knowledge.

Is a 5881 a member of the 6L6 family, like KT66s?

In other words, can an amp that normally takes 6L6s or KT66s be adjusted to take a 5881?

What would sound different with a 5881, and what would need to be modified in the amp?

Pardon my ignorance, and thanks for replies...

Kiwi

 

[Roccaforte Amps]

Originally posted by Kiwi
A dumb Q, for Doug and others ... I have zero tech knowledge.

Is a 5881 a member of the 6L6 family, like KT66s?

In other words, can an amp that normally takes 6L6s or KT66s be adjusted to take a 5881?

What would sound different with a 5881, and what would need to be modified in the amp?

Pardon my ignorance, and thanks for replies...

Kiwi

The 5881 tone depends on the circuit you put it in.
You can sub these tubes in their circuits most of the time,
but you really need to make sure the amps voltage doesn't exceed the 5881's ratings which are lower than that of a 6L6GC and a kt66.
In most 6L6GC based amplifiers you can use;
6L6GC,KT66,7581A,EL37,5881 without any problems, but rebiasing may be required. KT66's don't fit Fender chassis too well.
Some late Fenders (Rivera designed) have UL output stages running output tubes as high as 540V, do not install 5881's or EL37's in these amps, they'll fry for sure.
When in doubt, ask a tech what you have and can do. Doug

 

[waxnsteel]

Originally posted by Roccaforte Amps
Looks cheezy? Its damn near exact. You try them and see what you think, I'm impressed, and I stock hundreds of the originals.

I'm guessing he wants em "relic'ed". Maybe they look too new. Crazy how new things tend to do that.

 

[PlexiBreath]

Sounds like a tube I'd like to try in my '61 brown Concert.

 

[Kiwi]

Thanks, Doug, for the tech notes. One more Q:

- What would be the differences in sound and feel of 5881s over 6L6s and/or KT66? I've got several amps that take those two.

Thx - K