thanks for the replies, soon after I had posted i found an rca datasheet at this address:
http://www.pmillett.addr.com/tubedata/HB-3/masterindex.html
the lead id makes more sense now
http://www.pmillett.addr.com/tubedata/HB-3/masterindex.html
the lead id makes more sense now
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Sch3mat1c said:I have a pair of those... equivalent to the classic 6CW4 IIRC. So yeah... use wherever a 6CW4 might be used...
Might well be better sold to the vintage radio crowd, IIRC they aren't that cheap these days. A 12AU7 is cheaper, more linear (IIRC) and easier to find sockets for.
Tim
the Nuvistor sockets show up on EBay from time to time. I used 6CW4's in 50MHz and 144 MHz converters back in the 1960's
Not quite, same pinout but 7586 has mu=35 and Cgp=2.2p, 6CW4 has mu = 65-70 and Cgp=0.9p. 7586 is actually similar to 1/2 6DJ8, 6CW4 is more like 6HA5 or other frame grid triodes. I've been able to sub 6CW4 for 7586 in CFs in HP3400 RMS meters, but you probably couldn't use a 7586 in an RF circuit designed for 6CW4 or for a plate loaded amplifier with gain of 40.
BTW, be careful about microphonics especially in the 5 - 15kHz range, you'll need some mechanical isolation.
found 4 nuvistors & bases on ebay,in the process of building this design.http://www.tnt-audio.com/clinica/preamble_n.html any opinions?
The valve bases were mounted on a bracket, so the pre amp stage connections are all point to point. I used precision resistors in the signal path, roederstein/vishay coupling caps,silver wiring & a "blue" alps pot. At the moment i only have one input wired with rg178 coax (single braid shield,silver plated copper) I will be trying different cables for each input connection (rg400 coax,pure silver wire) Of course the use of the exotic parts is not for everyone & worthy of debate,
to my ears it sounds good-very good in fact, clean with good sound stage & imagery. I didn't know what to expect while building it because I had just been using the variable output of my cd player into my power amp, but i'm impressed.
to my ears it sounds good-very good in fact, clean with good sound stage & imagery. I didn't know what to expect while building it because I had just been using the variable output of my cd player into my power amp, but i'm impressed.
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7586 versus 6CW4
Mr1
Does'nt that Pre-Amble amp call for the 6CW4?
As someone earlier said, the 7586 has a Mu of 35, while the CW4, has a Mu of 70.
Did you find any problems subbing the 7586 for the CW4 in this scheme?
Unfortunately, The 6CW4, has become somewhat expensive as the Tube Microphone croud use them.
Although, the 2CW4 and the 8393 as well as the 13CW4 are still a great alternative and have a similar Mu and other specs,
I got 5 2CW4 off fleabay a while back for 9 bux--Great NOS ones, and work well, although the heaters are 2 volt, and for some reason take a couple of seconds longer to warm up to full emission--Greater mass maybe.....
Only real differences are the heater voltages, Easy for us lot--We dont really care what the heater volts is, because we can make our PSU's to suit!-
-Thats what I love about this game, We dont have to follow the croud with expensive tubes!
Mr1
Does'nt that Pre-Amble amp call for the 6CW4?
As someone earlier said, the 7586 has a Mu of 35, while the CW4, has a Mu of 70.
Did you find any problems subbing the 7586 for the CW4 in this scheme?
Unfortunately, The 6CW4, has become somewhat expensive as the Tube Microphone croud use them.
Although, the 2CW4 and the 8393 as well as the 13CW4 are still a great alternative and have a similar Mu and other specs,
I got 5 2CW4 off fleabay a while back for 9 bux--Great NOS ones, and work well, although the heaters are 2 volt, and for some reason take a couple of seconds longer to warm up to full emission--Greater mass maybe.....
Only real differences are the heater voltages, Easy for us lot--We dont really care what the heater volts is, because we can make our PSU's to suit!-
-Thats what I love about this game, We dont have to follow the croud with expensive tubes!
the preamp designer had tried 6cw4's in place and said there was a minor rise in distortion. midway through construction my work moved to a new premises and while destroying & throwing away unserviceable units i found 4 sylvania NOS 6cw4's, they were for use in an old DME unit. haven't tried them yet but will soon.last photo, the regulator board-a bit rough but it works well.
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