7591a tube
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7591a tube
has anybody used a 7591a for a power tube ?
what would you need to do to put them in a 18watt lite??
I have some stereo amps with 7591 that I could use
my 18watt liteIIb has octal sockets wired for 6v6
stanb
what would you need to do to put them in a 18watt lite??
I have some stereo amps with 7591 that I could use
my 18watt liteIIb has octal sockets wired for 6v6
stanb
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- Shrapnel
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http://www.nj7p.org/Tube4.php?tube=7591A http://www.nj7p.org/Tube4.php?tube=7591A
See there for the data on your tube/valve.
Can't seem to locate a replacement type other than the 7591.
See there for the data on your tube/valve.
Can't seem to locate a replacement type other than the 7591.
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Rock and Roll Aint Noise Pollution, neither is my amp
- PeterS
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I built a plexi with them and I really like it. It puts out about 30 watts. I think they would sound awesome in a 18-watt lite type circuit and plan on doing that someday. They have a higher voltage gain than most of the other octals, more like the EL84, so the stock PI should work quite nicely.
Matt.
Matt.
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- Shrapnel
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According to the link I gave earlier, they gave the basic specs for Cathode Bias 28watt P-P, & Fixed Bias 30watt P-P, Fixed Bias 45watt P-P, and [Fixed Bias] 11watt SE. RCA Recieving Tube Manuals RC23 & RC25 confirm. (My Sylvania manual would need to be dug out to double check with it.)
I'm sure there's a way to get it into the 18watt zone.
Double checked in my 1964 SAMS Tube Substitution Handbook and the only sub mentioned there was a 7591A for a 7591 (and not vice-versa.)
I'm sure there's a way to get it into the 18watt zone.
Double checked in my 1964 SAMS Tube Substitution Handbook and the only sub mentioned there was a 7591A for a 7591 (and not vice-versa.)
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Rock and Roll Aint Noise Pollution, neither is my amp
- jimipage33
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"AFFORDABLE??"
Only if you use the EH/SOVTEK modern "equivalent"
The originals are priced like GE6550a or GEC KT88. They are/were a GREAT tube used in the outputs of countless stereos (Pioneer, Fisher, etc.) and many AMPEG combo guitar amps. Many years ago, a group of people from "overseas" bought up virtually all of the remaining stocks...Prices went up accordingly. Until recently there was no substitute/replacement. In my limited experience, the EH tube works well but doesn't hold a candle to the originals (in my Fisher 500C) Haven't tried to build a new amp with 'em, though.
Tom
Only if you use the EH/SOVTEK modern "equivalent"
The originals are priced like GE6550a or GEC KT88. They are/were a GREAT tube used in the outputs of countless stereos (Pioneer, Fisher, etc.) and many AMPEG combo guitar amps. Many years ago, a group of people from "overseas" bought up virtually all of the remaining stocks...Prices went up accordingly. Until recently there was no substitute/replacement. In my limited experience, the EH tube works well but doesn't hold a candle to the originals (in my Fisher 500C) Haven't tried to build a new amp with 'em, though.
Tom
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thanks guys I just mite try it , I have a fisher 500c , scott , and a sansui
tube amps with good tubes and Iron . they all use 7591a out put tubes,
my fisher 500c is my main stereo, nothing plays back good guitar made with good tube amp than a tube stereo.
so the PI in the 18watt liteII has gain to power the 7591. I was thinking
I would need to lower cathode res. or maybe the tail res.
stanb
tube amps with good tubes and Iron . they all use 7591a out put tubes,
my fisher 500c is my main stereo, nothing plays back good guitar made with good tube amp than a tube stereo.
so the PI in the 18watt liteII has gain to power the 7591. I was thinking
I would need to lower cathode res. or maybe the tail res.
stanb
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- Shrapnel
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Those voltages will get you 45 watts in fixed bias, but you have to go a little more conservatively on the screens (slightly lower voltage, larger screen resistors) in a guitar amp or else they will glow, at least that's my experience. Check the RCA datasheet for cathode bias values, I think they recommend a higher primary Z and you'll of course get less power out. These tubes can sound fantastic though.Shrapnel wrote:What kind of output power do you figure you are getting with that recipie? 6k6 primary?jimipage33 wrote:my recipe:
plates at 450v
screens at 400v
cathode bias resistor at 180-200 ohms
bypass cap at 100 - 220uf
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- jimipage33
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Actually using OT's with a 4k2 primary, but running them at 8k4. I'm guessing upwards of 30 watts. Believe me, it's plenty loud.Shrapnel wrote:What kind of output power do you figure you are getting with that recipie? 6k6 primary?jimipage33 wrote:my recipe:
plates at 450v
screens at 400v
cathode bias resistor at 180-200 ohms
bypass cap at 100 - 220uf
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