Brand New Tung-Sol Reissue 7581A KT66 Current Matched Quad (4) Vacuum Tubes

Name: Brand New Tung-Sol Reissue 7581A KT66 Current Matched Quad (4) Vacuum Tubes
Brand: Tung-Sol
Price: 151.94 GBP
Availability: InStock
Rating: 4.9 (20 reviews)

VIVA TUBES

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US $204.70

Approximately£151.94

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6 available61 sold

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Free collection in person from Easthampton, Massachusetts, United States

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Located in: Easthampton, Massachusetts, United States

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Last updated on 21 Aug, 2025 19:12:43 BSTView all revisionsView all revisions

Item specifics

Type: Vacuum Tube

Brand: Tung-Sol

Model: 7581A

Country/Region of Manufacture: Russian Federation

MPN: 7581A

UPC: 609722163415

Item description from the seller

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I certify that all my selling activities will comply with all EU laws and regulations.

About this seller

Joined Apr 2001

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Your friendly trusted tube store. Always tested, matched, and guaranteed. Tubes tested on professional equipment with regulated power supplies. Affordable worldwide shipping, excellent customer ...

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Detailed seller ratings

Average for the last 12 months

Accurate description

5.0

Reasonable postage cost

4.9

Delivery time

5.0

Communication

5.0

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t***t (196)- Feedback left by buyer.
Past month
Verified purchase
Shipped / delivered super quick, packaging was perfect, and item was in incredible condition. One hundred percent would recommend this seller and would buy from this seller again.
s***j (133)- Feedback left by buyer.
More than a year ago
Verified purchase
Amazing tubes, massive headroom in my dual rectifier. In my opinion way better than a standard 6l6. Viva tubes are on it thank you. Will purchase again
l***a (1596)- Feedback left by buyer.
More than a year ago
Verified purchase
Always an excellent source for vacuum tubes of all types. Have purchased for both home and work use. Tubes are securely packed with quick delivery. Thank you! 5*!

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4.9

20 product ratings

18 users rated this 5 out of 5 stars
2 users rated this 4 out of 5 stars
0 users rated this 3 out of 5 stars
0 users rated this 2 out of 5 stars
0 users rated this 1 out of 5 stars

Would recommend

Good value

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Most relevant reviews

See all 17 reviews

by slmccaul01
05 Jan, 2019Most favourable review
Tung-Sol 7581A Power Tubes
After reading some reviews online I thought I would give them a try in my PrimaLuna Prologue Premium integrated amp. I have tried several tubes in the past year including Tung-Sol KT150, Siemens RFT EL34, SED Winged C EL34, Gold Lion KT77 reissue and the latest Mullard EL34 reissue. So far my favorite as been the GL KT77's as they have the somewhat sweet midrange of the EL34's but have extended bass and treble plus a huge 3 dimensional soundstage. I've had the 7581A's in the amp for about 8 hours now and I can say with confidence these tubes rival the best I've heard. They have full spectrum sound along with a large soundstage plus great tone like mose of the EL34 types I have heard. I would recommend these tubes for those that want nearly the best out there at a fraction of the cost of ... After reading some reviews online I thought I would give them a try in my PrimaLuna Prologue Premium integrated amp. I have tried several tubes in the past year including Tung-Sol KT150, Siemens RFT EL34, SED Winged C EL34, Gold Lion KT77 reissue and the latest Mullard EL34 reissue. So far my favorite as been the GL KT77's as they have the somewhat sweet midrange of the EL34's but have extended bass and treble plus a huge 3 dimensional soundstage. I've had the 7581A's in the amp for about 8 hours now and I can say with confidence these tubes rival the best I've heard. They have full spectrum sound along with a large soundstage plus great tone like mose of the EL34 types I have heard. I would recommend these tubes for those that want nearly the best out there at a fraction of the cost of most. These are truly fantastic tubes and an incredible value.
Verified purchase: YesCondition: NewSold by: onlyglass
by thebic125
10 Jun, 2020
Very closely matched in circuit, great sound rivaling old blackplates.
These replaced rca blackplates circa 1960 which were still good. I've only used 2 of these so far, but in circuit I was able to bias them within 0.5ma, which is really closely matched. Immediately it sounded great, but then I cranked up the bias current to a hotter 50ma (up from 35) which this tube is designed to support, and wow! I think I've found my new 6l6 tube type!
Verified purchase: YesSold by: vivatubescom
by okamilumen
30 Nov, 2020
Great sound tube, like a 6L6 on steroids
After reading some reviews on this tube, I bought a set to replace the 6550 tubes I was using. To me, these have a more natural sound than the 6550 Sovteks, with a lusher midrange, but still has extended highs and great bass. Should produce less total power than the 6550's , but so far I haven't noticed any real decrease in output. Just make sure your amp can use these, or can be re-biased to use these. Highly recommended.After reading some reviews on this tube, I bought a set to replace the 6550 tubes I was using. To me, these have a more natural sound than the 6550 Sovteks, with a lusher midrange, but still has extended highs and great bass. Should produce less total power than the 6550's , but so far I haven't noticed any real decrease in output. Just make sure your amp can use these, or can be re-biased to use these. Highly recommended.
Verified purchase: YesCondition: New
by hlhuston8
04 Jun, 2017
7581A
I recently got back into playing guitar after a lengthy hiatus. I've aged a bit and high-gain tube amps are no longer my idea of good tone. Nowadays I'm into volume controlling the amount of grit I play with. I've re-tubed my pre-amp with 5751s and left the Winged =C= 6L6GC that I put in there at least 10+ years ago. While shopping around for tubes online that I really didn't need, (who does that?), I stumbled across some mumblings about Svetlana no longer being the same company that it used to be. They sold out and the Winged =C= tubes are now going for a premium. I figured that I might want to pull those tubes out to set aside and look for a replacement. 1st things 1st: I use a Carvin MTS 3200 head into their open-back 2x12 cabinet. I replaced the stock speakers with Eminence ... I recently got back into playing guitar after a lengthy hiatus. I've aged a bit and high-gain tube amps are no longer my idea of good tone. Nowadays I'm into volume controlling the amount of grit I play with. I've re-tubed my pre-amp with 5751s and left the Winged =C= 6L6GC that I put in there at least 10+ years ago. While shopping around for tubes online that I really didn't need, (who does that?), I stumbled across some mumblings about Svetlana no longer being the same company that it used to be. They sold out and the Winged =C= tubes are now going for a premium. I figured that I might want to pull those tubes out to set aside and look for a replacement. 1st things 1st: I use a Carvin MTS 3200 head into their open-back 2x12 cabinet. I replaced the stock speakers with Eminence GHB128. Combined with various 5751 & Winged =C= 6L6 tubes, it has a very classic sound. Useful across many genres & decades of music. Very versatile. I run it with only 2 power tubes. 2nd, the Winged =C= 6L6s are AMAZING tubes! Beautiful, balanced, detailed & rich. Finding a close replacement is probably not going to happen very easily. But I did stumble onto these 7581As that got rave reviews that compared them to SED Winged =C= 6L6, and got a matching quad. 2 to use, 2 to have on standby. The drive channel is dimed. Always. This is a very nice tube. Having played them a bit, I've found they have more deep bass, very controllable mids, highs that shimmer beautifully and SUSTAIN! Holy cow do these bottles sustain! Imagine a lower gain pre-amp made up of 5751's, a drive channel that was set at about 6 with 6L6 tubes, EQ all left the same. I install 7581A's, I end up reducing the drive to around 4, turn up the mids a couple and I have a sustaining crunch that is rich, detailed with added headroom & very low noise. I did adjust my picking a bit so I'm not so heavy on the low E string due to the deep bass of the tube. I made no EQ adjustment to the clean channel. It was OMG crystal clear all around. V3 is on that channel and it has a JJ 5751 in it, which is very bell-like in itself. The low E was thundering so hard that my reverb was chattering with it being turned off. I went to the shop to get some 1/4" dense foam to put under the feet of the head to keep it from ratling the reverb box in the head cabinet; it was that deep & thundering! Again, now I have to control how hard I pick that E string with these tubes installed. The mids & highs were clear and bell-like and round. Very, very pleasing to my ears. The lows can be a little pronounced. So much that turning the low EQ down makes the overall sound a little thin. It required me to adjust my picking slightly for a more balanced sound. But don't fear that. Bottom line: it will take a little tinkering to get things right. I need to learn it. I wouldn't compare it to a Winged =C= 6L6 at all. It has its very own identity and has high potential to be its own legendary tube. Delish. Enjoy!
Verified purchase: YesSold by: wpc1896
by eljefe111
01 May, 2017
The 7581A Beam Pentode Offers An Alternative To Those Looking For A Change!
Since the Winged =C= factory in St. Petersburg Russia stopped making those glorious almost bulletproof line of power tubes the mainstay replacement for all of our Avian Series amplifiers has always been the Svetlana 6L6GC. It has been a bit of a let-down as to quality and more importantly durability. To be honest though, lately the sound has been fairly close to the originals, especially over the last two to three years. Then a few weeks back along comes one of my customers telling me about this "guitar amplifier" tube that he tried out in his amplifier.... and that I should try it. Apprehensively I started reading about it first.... then I purchased a quad to try out. Since then I have purchased 2 more quads. To tell you the truth... I am pretty excited about this power tube. So ... Since the Winged =C= factory in St. Petersburg Russia stopped making those glorious almost bulletproof line of power tubes the mainstay replacement for all of our Avian Series amplifiers has always been the Svetlana 6L6GC. It has been a bit of a let-down as to quality and more importantly durability. To be honest though, lately the sound has been fairly close to the originals, especially over the last two to three years. Then a few weeks back along comes one of my customers telling me about this "guitar amplifier" tube that he tried out in his amplifier.... and that I should try it. Apprehensively I started reading about it first.... then I purchased a quad to try out. Since then I have purchased 2 more quads. To tell you the truth... I am pretty excited about this power tube. So far it works nicely in more of our products than it doesn't. It seems like I probably need to spend a little more time on these, but it certainly is worth a shot! I notice immediately a little bit more power, punch, depth and delineation of sound stage. But not on every speaker... and not on every amplifier. I cannot quite put my finger on it yet, but there will certainly be more to come. To those looking for a slight increase in power and more headroom, this may just be the ticket. As usual its going to depend on the actual amplifier, the speaker/drivers, the room, and all the normal moving parts that go into tube audio. For the price though... you really can't go wrong. So far though, the results are very positive overall. As they break in I am sure they will only get better.
Verified purchase: YesSold by: wpc1896

Brand New Tung-Sol Reissue 7581A KT66 Current Matched Quad (4) Vacuum Tubes

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VIVA TUBES

99.8% positive Feedback•84K items sold

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Most relevant reviews

Tung-Sol 7581A Power Tubes

Very closely matched in circuit, great sound rivaling old blackplates.

Great sound tube, like a 6L6 on steroids

7581A

The 7581A Beam Pentode Offers An Alternative To Those Looking For A Change!

More to explore:

VIVA TUBES

99.8% positive Feedback•84K items sold

Detailed seller ratings

Popular categories from this shop

Seller Feedback (44,350)

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Brand New Tung-Sol Reissue 7581A KT66 Current Matched Quad (4) Vacuum Tubes

Shop with confidence

Item specifics

Item description from the seller

Seller business information

VIVA TUBES

99.8% positive Feedback•84K items sold

Detailed seller ratings

Popular categories from this shop

Seller Feedback (44,350)

Product ratings and reviews

Most relevant reviews

Tung-Sol 7581A Power Tubes

Very closely matched in circuit, great sound rivaling old blackplates.

Great sound tube, like a 6L6 on steroids

7581A

The 7581A Beam Pentode Offers An Alternative To Those Looking For A Change!

More to explore:

Related Searches