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Tung-Sol

New Matched Pair (2) Tung-Sol 7581A Vacuum Tubes

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SKU:
NP085-2
UPC:
609722163415
MPN:
Pair 7581A
Availability:
Ships in 1 business day or less.
Shipping:
Calculated at Checkout
On Sale
Now: $83.01
Was: $92.23

Description

New Plate Current Matched Pair of Tung-Sol 7581A (KT66) Vacuum Tubes

The Tung-Sol 7581A is rated at a higher 35 watts compared to the standard 7581 or 6L6GC. This tube is a direct substitute for the KT66, and is in fact a version of the KT66. These Tung-Sols were built to last with a very large plate structure and many heat dissipaters for reliability. The 7581A has a very warm tone and gives you much more headroom if ran in place of a standard 6L6GC.

Will work in place of: 7581A, 7581, KT66

Testing and/or Matching

At VIVA TUBES, all of our customers get the same high standard of testing and matching. Some sellers charge more for premium matches but we believe all of our customers should get the same level of quality and service. 

Tubes are tested and/or matched at full operating voltage with regulated power supply on a Maxi Matcher tester for general mutual transconductance (Gm). In addition, power tubes are tested/matched by plate current (Ip) and preamp tubes are tested/matched by gain. Rectifier tubes will be tested for emissions on a calibrated military grade tube tester. 

Our goal is to match within 5% with an upper limit of 15% (15% is the industry limit to consider a set).

Hand written test data included.

Note that we do offer a few models which are tested & matched at the factory. They will be matched by the same parameters (Ip & Gm) but to the manufacturer's standards. Factory testing will be indicated in the item title and description. 

Guarantee

We offer a minimum 90 day guarantee covering functional defects - including noise unless otherwise stated. The guarantee period begins the day you receive your order.

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Additional Information

reverb_offers:
off
reverb_model:
7581 7581A KT66
reverb_condition:
Brand New
reverb_shipping_profile:
$12.99
reverb_upc_does_not_apply:
on
Item Type:
Vacuum Tubes
Production Era:
New/Current Production
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1 Review

  • 4
    Tung Sol 7581A

    Posted by G on 5th Feb 2021

    Four stars for my application, though I am certain these would be 5-star homeruns for many others I got these tubes to try out in an Ampeg PF-50T bass head, which I have been running with Tung Sol 6L6GC-STR power tubes, Tung Sol Gold Pin 12AX7 preamp tubes, and a Genelex Gold Lion Gold Pin 12AU7 master/PS. All matched, balanced, and selected for low noise. I have been extremely happy with the sound from my basses--Jazz, Precision or Stingray played through an Aguilar SL410--but, as many tube lovers get, I am always curious about trying new combinations. So, based on trusted advice, I picked these up for some rolling. After running them in for a full day and setting and rechecking the bias, I can say that these are extremely powerful tubes--significantly more so than the already-beefy 6L6GC STRs. The 7581As are airy and wide, too. Tons to like about them. However, they reach the edge of breakup just a bit earlier in the music when I play, if that makes sense. Almost more sensitive, which can be great for some. They are a touch edgier in that breakup than the 6L6GC STRs and not as fat or smooth to my ear or in my setup. Where the 6L6GC STRs shove with authority the 7581As jab with power and snap. They sound a bit more like KT88s--again, great for being louder and for width, but not as right for me as the STRs, which are as good or better sounding to me with my gear than any other 6L6 I have tried, whether NOS or other great reissues. Bottom line: I am glad I tried the 7581As and happy to have them as backups or for when I might need more of what they give to cut through, but I put the STRs back in for everything else.

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