Yes I bring my boards, there are several unmodified Haflers there, and the Perreaux 3150 chassis and power supply for a high powered version.
I recapped and CLC filtered the Perreaux‘s power supply so I can’t use the original Hitachi 135/50 devices because now it doesn’t sag enough at full power to stay within the Voltage breakdown limits of the Hitachis. Rails are +/-95 volts.
I have matched sets the higher voltage and current K176/J56 Hitachi devices and a set of the double die TO3 Exicons. The heatsink is drilled for 3 of each device And before some-ones says it can’t work ( Syn08 possibly), remember this amp is 33 years old and had the original output devices still running In it.
I recapped and CLC filtered the Perreaux‘s power supply so I can’t use the original Hitachi 135/50 devices because now it doesn’t sag enough at full power to stay within the Voltage breakdown limits of the Hitachis. Rails are +/-95 volts.
I have matched sets the higher voltage and current K176/J56 Hitachi devices and a set of the double die TO3 Exicons. The heatsink is drilled for 3 of each device And before some-ones says it can’t work ( Syn08 possibly), remember this amp is 33 years old and had the original output devices still running In it.
It will work, since these are self protecting lateral mosfets and therefore won’t blow in your face, but I would not hope to get much current out of them. They still have only 1S transconductance, which will drop with the drain current and the temperature.
It’s going to use Bob Cordell’s new Hafler output stage driver board the Rick has been collaborating with Bob on - to run the shop speakers (100db @ 1 watt) - 2 pairs of them with about 3 ohm minimum load in the bass, most of the time they’ll be running at less than a watt or 2 - except when I play them too loud at Diyaudio meets.
My question will be can I use 3 pairs of the double die 16 amp Exicons to get a higher current output capability that maybe I can’t bias high enough because of heatsink limitations, or stick with the lower current single die 7 amp Hitachis and bias them harder.
My question will be can I use 3 pairs of the double die 16 amp Exicons to get a higher current output capability that maybe I can’t bias high enough because of heatsink limitations, or stick with the lower current single die 7 amp Hitachis and bias them harder.
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The double dies exicons will simply double the available current, you can think of 3 exicons as 6 hitachis in parallel.
The problem with these laterals is the large idle power dissipation due to the high required bias. It is hard and doesn’t make much sense to bias them under the zero tempco point (about 150 mA per transistors) meaning that 3 exicons will need almost 1A bias. You do the math for the power you have to dissipate before getting 1W of output power.
Great to see everyone again! Thanks Dave for being an awesome host. Most appreciated.
Twitchie/Stephen, thanks again for knocking one off my bucket list. Most enjoyed finally hearing a Pass SIT amp. Sounds like (good) triodes to me.
Once again, thank you Dave for hosting the get together. It was great seeing familiar faces, and new one (Stephen). Really enjoyed the SIT amp that Stephen brought, and the different preamps hooking up to it.
A special thank you to Rick for bringing the Audio analyser to measure my preamp (and found out that I have the channels switched).
Wish everyone a Merry X'mas and a happy holiday season!! See you guys in the new year year!
Regards,
A special thank you to Rick for bringing the Audio analyser to measure my preamp (and found out that I have the channels switched
). Wish everyone a Merry X'mas and a happy holiday season!! See you guys in the new year year!
Regards,
Thanks to Dave for hosting and for everyone who brought projects to listen to. I did a horrible job of putting names to online aliases but it was great meeting everyone today and a hugely fun gathering.
Regarding the dac I was asking about, if you can send me details, I'd like to see if I can get one as well. You've sold me on the USB interface.
Happy Holidays to everyone and see you in the new year!
@Dennis, thanks for the bag of goodies from BAF!
Regarding the dac I was asking about, if you can send me details, I'd like to see if I can get one as well. You've sold me on the USB interface
.Happy Holidays to everyone and see you in the new year!
@Dennis, thanks for the bag of goodies from BAF!
Thanks to Dave for hosting and for everyone who brought projects to listen to. I did a horrible job of putting names to online aliases but it was great meeting everyone today and a hugely fun gathering.
Regarding the dac I was asking about, if you can send me details, I'd like to see if I can get one as well. You've sold me on the USB interface
Happy Holidays to everyone and see you in the new year!
@Dennis, thanks for the bag of goodies from BAF!
Stephen
Here is the link
Tone Board: Hi-Res Audio Board Designed for Music Fanatic.
I believe Audiosciencereview.com has measurements on this DAC board. You can check it out. See you next time.
Regards,
A big thanks to Dave for graciously hosting this event. It was my first time attending
and it was really great meeting so many local diyers.
Hearing Stephen's SissySIT should be the impetus needed for me to start working on
mine...
Cheers,
Dennis
Ooops! I forgot to mention this is also Dennis's debut appearance!!
Now, I know whom to talk to when I start working on my F5T.
See you next time!
Regards,
Sorry I couldn't make it again! I would have liked to hear that SIT amp
At least my mate got to work on time. And as a bonus, I chased out an annoying noise in my preamp. Turns out using a crappy boost module, even on a 6E2 meter can find it's way back into the audio stream.
Next meet up I could bring one of my unconventional tube amps if there's interest. They are unwieldy (PITA) but I can bring it along...
At least my mate got to work on time. And as a bonus, I chased out an annoying noise in my preamp. Turns out using a crappy boost module, even on a 6E2 meter can find it's way back into the audio stream.
Next meet up I could bring one of my unconventional tube amps if there's interest. They are unwieldy (PITA) but I can bring it along...
