| kenev |
I need your help deciding on which transconductance amp is most suited for driving a pair of Fostex drivers.
I have a pair of FE167E in TQWPs (aka Voigt Pipes) and also a pair of FE206E waiting for a pair of BLHs to be built. Having read Nelson Pass's paper on current driven full-range drivers, I have already built a vacuum tube transconductance amplifier, which sounds absolutely marvellous with the Fostexes.
But, I also want to build a solid state transconductance amplifier. So, having read a large number of posts here, I will have to decide which of the two mentioned (ZV9 or F2) would be better suited for my case.
Any help from the experts here will be welcomed.
Regards,
Evangelos |
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| vitalstates |
Hi Kenev
I'm sorry I can't answer the question but I'm about to finish an F2 to drive a pair of 206E voigt pipes (see web page).
But I am intrigued by your mention of transconductance valves....any chance of some detail??
Regards
Ed |
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| kenev |
Hi Ed,
Here is a link to the mentioned amplifier:
http://www.audioasylum.com/scripts/...gnequest&m=5167
I have made a change to the original schematic: I use a ccs fed shunt regulated voltage supply for the screens, using Gary Pimm's CCS and a stack of 0A2 and 0B2 VR tubes, for about 255 volts between screen and cathode. Sounds much better this way.
Originally, I had built the lower power EL84 version (ca. 2.5W)
http://www.audioasylum.com/scripts/...gnequest&m=2553
but there was a lack of power, more evident on loud passages and dynamic parts, so I went for the higher power version. Note that, even it is titled a "9W amp", to get those 9 watts, you have to increase B+ to a much higher voltage in order to increase the tube's power dissipation to 36W. With a B+ of 450V, as shown, power dissipation is 24W, so output power is around 6 watts, not bad for a Fostex. I'm using KT88s. Had tried EL509s, but there were producing a lot of distortion.
Regards,
Evangelos |
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| Vix |
| ZV9, if you can obtain the Jfets. If not, an F2 will work. |
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| Brett |
| Evangelos, I'm curios about your tube amps, but can't get into the AA links provided. Could you post here or provide other info on them please? |
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| stefanobilliani |
The ZEN V9 is cool becouse with a couple of switches you can alternate between current source and voltage amplifier . And choose for yourself or sometime also for the music you are listen to . In courrent source mode dont forget to load the output with a power resistor wich is 22ohm for the FE206E .
Use the best ( non inductive ) power resistors avaiable , and match well the J fets
:cool: |
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| kenev |
| quote: | Originally posted by Brett
Evangelos, I'm curios about your tube amps, but can't get into the AA links provided. Could you post here or provide other info on them please? |
Brett, I just tried the links mentioned above and they work fine. I don't know why you can't open them. Maybe you could try again. |
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| Brett |
Works fine now. It asked for username and password before and then rejected my valid AA info.
Cheers. |
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| kenev |
| quote: | Originally posted by Brett
Works fine now. It asked for username and password before and then rejected my valid AA info.
Cheers. |
That's good. Have a nice reading!
Regards,
Evangelos |
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