T-7591-S-JJ-MP - Apex Matched Pair version | Body Height | 93 mm |
Cathode Current (Ik) | ≤ 85 mA |
Filament Current (If) | 0.8 A |
Filament Voltage (Uf) | 6.3 V |
Gain (μ) | 16.8 |
Grid 2 dissipation (Wg2) | 3.3 W |
Grid Circuit Resistance (Rg), Cathode Bias | 1 MΩ |
Grid Circuit Resistance (Rg), Fixed Bias | 0.3 MΩ |
Grid Current 2 (Ig2) | 8 mA |
Grid Voltage 1 (Ug1) | -10 V typical |
Grid Voltage 2 (Ug2) | ≤ 440 V, 300 V typical |
Grid capacitance (cg1) | 10 pF |
Grid to Plate Capacitance (ca/g) | 0.25 pF |
Item Diameter | 33.3 mm |
Item Height | 79 mm |
Plate Capacitance (ca) | 5 pF |
Plate Current (Ia) | 60 mA |
Plate Dissipation (Wa) | ≤ 19 W |
Plate Voltage (Ua) | ≤ 550 V, 300 V typical |
Transconductance (S) | 10 mA/V |
T-7591-S-JJ-MQ - Apex Matched Quad version | Body Height | 93 mm |
Cathode Current (Ik) | ≤ 85 mA |
Filament Current (If) | 0.8 A |
Filament Voltage (Uf) | 6.3 V |
Gain (μ) | 16.8 |
Grid 2 dissipation (Wg2) | 3.3 W |
Grid Circuit Resistance (Rg), Cathode Bias | 1 MΩ |
Grid Circuit Resistance (Rg), Fixed Bias | 0.3 MΩ |
Grid Current 2 (Ig2) | 8 mA |
Grid Voltage 1 (Ug1) | -10 V typical |
Grid Voltage 2 (Ug2) | ≤ 440 V, 300 V typical |
Grid capacitance (cg1) | 10 pF |
Grid to Plate Capacitance (ca/g) | 0.25 pF |
Item Diameter | 33.3 mm |
Item Height | 79 mm |
Plate Capacitance (ca) | 5 pF |
Plate Current (Ia) | 60 mA |
Plate Dissipation (Wa) | ≤ 19 W |
Plate Voltage (Ua) | ≤ 550 V, 300 V typical |
Transconductance (S) | 10 mA/V |
T-7591-S-JJ - Single version | Body Height | 93 mm |
Cathode Current (Ik) | ≤ 85 mA |
Filament Current (If) | 0.8 A |
Filament Voltage (Uf) | 6.3 V |
Gain (μ) | 16.8 |
Grid 2 dissipation (Wg2) | 3.3 W |
Grid Circuit Resistance (Rg), Cathode Bias | 1 MΩ |
Grid Circuit Resistance (Rg), Fixed Bias | 0.3 MΩ |
Grid Current 2 (Ig2) | 8 mA |
Grid Voltage 1 (Ug1) | -10 V typical |
Grid Voltage 2 (Ug2) | ≤ 440 V, 300 V typical |
Grid capacitance (cg1) | 10 pF |
Grid to Plate Capacitance (ca/g) | 0.25 pF |
Item Diameter | 33.3 mm |
Item Height | 79 mm |
Plate Capacitance (ca) | 5 pF |
Plate Current (Ia) | 60 mA |
Plate Dissipation (Wa) | ≤ 19 W |
Plate Voltage (Ua) | ≤ 550 V, 300 V typical |
Transconductance (S) | 10 mA/V |
Product Reviews
Out of 2 matched quads, (8 tubes), I have 2 that RED PLATE in a working Fisher unit. I put Tung-sols in and it works fine. I also notice that the "JJ's run very hot compared to the others.
I will never by "JJ" anything again. BAD, BAD tubes
Appears as ordered.
Out standing quality, price, and delivery!!! Brought new life to my 1961 Pilot 654MA!!!
Meh. Westinghouse, Tung Sol, or other USA 7591As will last 5-20x longer than JJs, and the A suffix simply sound better and last longer. I just put Westinghouse 7591As in a pair of Mc30s (Mc Intosh) monoblocks, and they were worth the $250 over the JJs. I consider the JJs to be one of the better 7591s but lately I have had some real problems with JJ not properly annealing their glass. I have never had any RCA, Westinghouse, GE or Tung Sol's bottle crack from the heat. Tung Sol as in Tung Sol made in USA not Mike Mathews' New Sensor reissue stuff from Russia. So far I haven't had too many problems with New Sensor tubes cracking from heat & cooling. That is mostly a JJ problem, and it's getting really old too.
I have used the JJ 7591 tubes in numerous customer amps over the past few years with good results. They sound good, and have bias levels similar to the originals, the supply of which continue to diminish.
I love having AES within a 30 minute drive. I can actually order something simple, like tubes, in the morning and pick it up that same day during their 90 minute window of opportunity. Their prices are great, they have what I need for most of my vintage tube stereo needs. Life is good
Scott 7591a works very well in my Scott 299c and LK-72 .
Tubes worked great in my 50 year old Ampeg amplifier. The people at Antique Electronic Supply, especially the person I spoke with (I think his name was Justin), were more than helpful in understanding what I needed, and getting me the difficult to find replacement tubes. Great product and great service.