You can use most of the 2A3's schematics for 45. The only difference is the cathode bias resistor should be changed from 750 ohm to 1.5K ohm.
Hi Kmtang, i know there a lot of 45 schematics, but not with the 6H30 as a driver. I'm interested in this tube.
Re: 45 SE
I like the "natty" corner blocks that I guess are to improve ventilation.Chul said:This is a 6H30-45 DC coupled SE amp.
The wood base, I wanted to have something like Chris Brady's 845.
This one is with power transformer! I was lucky to have a woodworker who did this for me.
The circuit..
Hi Dhaen and Stalker,
This 45 SE was for a very sensitive horn system with active woofer below 150Hz, Oris (something like Avant Garde). So I am not sure this circuit is for the higher ouput, but it was good in quality to me.
OPT is Sowter parafeed 5K, 45 active load is Gary Pimm's EL84 CCS, and load for 6H30 (each section per channel) is DN2540 CCS. 45 can be AC heated, but I was worried about the sensitive horn...
Cheers,
Chul
Hi Dhaen and Stalker,
This 45 SE was for a very sensitive horn system with active woofer below 150Hz, Oris (something like Avant Garde). So I am not sure this circuit is for the higher ouput, but it was good in quality to me.
OPT is Sowter parafeed 5K, 45 active load is Gary Pimm's EL84 CCS, and load for 6H30 (each section per channel) is DN2540 CCS. 45 can be AC heated, but I was worried about the sensitive horn...
Cheers,
Chul
Attachments
Re: Raven Preamp
Nice project! That looks like a lot of work to me. Nicely done!
Well designed kits really provide a valuable niche IMO. Can you imagine making all that from scratch starting with a few ideas in your head and scribbles on paper? Then you've got endless R&D, parts sourcing, chassis and circuit board manufacturing, etc. That could take years and you'd run a real risk of abandoning the project before completed. Trust mne on that!
Irakli said:Just finished my Raven Preamp (designed by Lynn Olson). took me long time but it was worth doing. Sounds great!
Nice project! That looks like a lot of work to me. Nicely done!
Well designed kits really provide a valuable niche IMO. Can you imagine making all that from scratch starting with a few ideas in your head and scribbles on paper? Then you've got endless R&D, parts sourcing, chassis and circuit board manufacturing, etc. That could take years and you'd run a real risk of abandoning the project before completed. Trust mne on that!
OK, it's not 100% finished yet, (nothing of mine is) but it looks it and I can't wait any longer to share it.
It's a headphone amp/Pre amp. Long tail pair 6DJ8 and 4 triodes paralleled cathode follower output 5687. Drives my 64 ohm Head phones beyond sane volumes, and sounds great. The PSU is 100W isolation transformer-20 ohm resistor-SS bridge-6000 uf Sprauge DX cap-.6H choke-2000uf cap-various resistors and 2000uf cap to each stage.
Bass is a little rolled off, but sound better this way than with the 'lytic cap parallel to the 33uf film. There was a weird 10 mv squareish wave across the output caps when playing that sounded harsh. I may try some boutique 'lytics some day.
I used up almost all of my 1/4" aluminum plate that I found in the scrap yard I've gotten good at drilling and tapping into the edge of 1/4" with 6-32 cap screws.
On to the picks.
It's a headphone amp/Pre amp. Long tail pair 6DJ8 and 4 triodes paralleled cathode follower output 5687. Drives my 64 ohm Head phones beyond sane volumes, and sounds great. The PSU is 100W isolation transformer-20 ohm resistor-SS bridge-6000 uf Sprauge DX cap-.6H choke-2000uf cap-various resistors and 2000uf cap to each stage.
Bass is a little rolled off, but sound better this way than with the 'lytic cap parallel to the 33uf film. There was a weird 10 mv squareish wave across the output caps when playing that sounded harsh. I may try some boutique 'lytics some day.
I used up almost all of my 1/4" aluminum plate that I found in the scrap yard I've gotten good at drilling and tapping into the edge of 1/4" with 6-32 cap screws.
On to the picks.
Attachments
The front controls. I have seperate Heater, B+, unmute so I can let the cathodes get good and hot before I put the juice to it. I still plan to make a mute board to be sure that the outputs are shorted for a few seconds after B+ comes on. 10V into a power amp is not good form.
Attachments
Check out the night view. Behind the knobs id 1/4" plexy that I sanded and edge lit with red LED's (blue and tubes go together like pickles and chocolate milk) There is also a peice of 1/2" glass that I need to order through a friend that will clamp to the bottom of the top plate and extend over the tubes and be edge lit.
Attachments
Re: Re: Raven Preamp
Thanks a lot
rcavictim said:
Nice project! That looks like a lot of work to me. Nicely done!
Thanks a lot
Hi all, I'm new here. Looks like a great place. Here is the latest DIY I've done
Love This STuff
Mark
Love This STuff
An externally hosted image should be here but it was not working when we last tested it.
Mark
aikido and jel300b
these are a couple of my more recent projects. first is a slightly revised version of a jel300b sporting mr. elliano's wonderful electraprint output trannys. base is 1/8" brushed aluminum plate with mdf base filled and painted black laquer and buffed to high gloss. all tranny ends are painted to match.
http://i27.photobucket.com/albums/c161/selfwilly/DCP_0007_0003.jpg
http://i27.photobucket.com/albums/c161/selfwilly/DCP_0004_0009.jpg
second is my aikido project i nicknamed "panhead". it's set up with four 6dj8's, and sounds awesome. both power supply and input stage are built on 8"x8" cakepans! i got this suggestion from john broskies site. the "dagmar" vol. knob is a cap from a tube of adhesive. it has replaced any preamp that i had used prviously in my system. eventually after more tweaking it will find a home in a finished chassis.
http://i27.photobucket.com/albums/c161/selfwilly/aikido2.jpg
these are a couple of my more recent projects. first is a slightly revised version of a jel300b sporting mr. elliano's wonderful electraprint output trannys. base is 1/8" brushed aluminum plate with mdf base filled and painted black laquer and buffed to high gloss. all tranny ends are painted to match.
http://i27.photobucket.com/albums/c161/selfwilly/DCP_0007_0003.jpg
http://i27.photobucket.com/albums/c161/selfwilly/DCP_0004_0009.jpg
second is my aikido project i nicknamed "panhead". it's set up with four 6dj8's, and sounds awesome. both power supply and input stage are built on 8"x8" cakepans! i got this suggestion from john broskies site. the "dagmar" vol. knob is a cap from a tube of adhesive. it has replaced any preamp that i had used prviously in my system. eventually after more tweaking it will find a home in a finished chassis.
http://i27.photobucket.com/albums/c161/selfwilly/aikido2.jpg
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