Here's a humble little project amongst all those super-amps!
Still awaiting real OPTs, connected to my DAW, the 50EH5 "Daddy" amp.
http://www.geocities.co.jp/Milano/1988/radio/50eh5.htm
Note external passive volume control, amp will eventually be on a shelf.
PB
Still awaiting real OPTs, connected to my DAW, the 50EH5 "Daddy" amp.
http://www.geocities.co.jp/Milano/1988/radio/50eh5.htm
Note external passive volume control, amp will eventually be on a shelf.
PB
Attachments
Those OPTs look OK but I'm reading less than 1K across the primary! Click on the web link in post 1 for the schematic. Very simple, does sound sweet though, considering it has to beat it's way through those transfos!
BTW - in deference to another thread, "yes Virginia there is an iso transformer in there." Actually 2 of them, I sneaked 100V by doing 120V to 15V fed back into the 17V secondry of #2 and back out the primary, made about 105V for less than $7!
PB
BTW - in deference to another thread, "yes Virginia there is an iso transformer in there." Actually 2 of them, I sneaked 100V by doing 120V to 15V fed back into the 17V secondry of #2 and back out the primary, made about 105V for less than $7!
PB
Have you seen mine?
http://www.t-linespeakers.org/tubes/SEP_50EH5.html
dave
An externally hosted image should be here but it was not working when we last tested it.
http://www.t-linespeakers.org/tubes/SEP_50EH5.html
dave
Must be flea amp season or something. Built this one to use with my iPod when I'm at work. Uses triode strapped 6BH6 direct coupled to a paralelled ECC82 which sits on an 0C2 instead of a cathode resistor.
Not a lot of power but sounds quite reasonable so-far.
Schematic here
Not a lot of power but sounds quite reasonable so-far.
An externally hosted image should be here but it was not working when we last tested it.
Schematic here
The circuit is based on the loftin-white theme. Because the grid of the output tube is directly connected to the plate of the driver, this must be about 14 volts negative to the output tube's cathode in order to bias the output tube correctly.
This is usually done by using a large cathode resistor on the output tube but I thought that a 150v regulator tube would generate less heat and look cool.
It seems to work ok but the 0C2 can only cope with 30ma max so this design couldn't be scaled up.
There might also be difficulties with bias stability during mains fluctuations as the cathode of the ECC82 will stay fixed at 150v while the plate of the driver will vary with the ht supply. In practice nothing bad has happened so-far
planet10 said:
Dave,
Instead of going to all that trouble to make those wee little tubes look bigger, why didn't you just use bigger tubes? 50L6?
Ducking for cover now. Actually really did you consider 50L6? The covers you use are sometimes used to deal with microphonics. Was that an issue with your 50EH5's?
Rob
rcavictim said:Instead of going to all that trouble to make those wee little tubes look bigger, why didn't you just use bigger tubes? 50L6?
Actually really did you consider 50L6? The covers you use are sometimes used to deal with microphonics. Was that an issue with your 50EH5's?
This amp is a rebuild of the amp in the flip-down TT unit my parents bought when i was 12. The tube coolers are floor sweepings (rejects) from a batch i helped pack up for England -- this amp is meant to be a caricature -- the tube coolers give it more... The website link has the whole story.
dave
My new amp
Hey!
Here's my newest offspring, a winged-C 6B4G SE amp, pre-amp stage is an winged-C EF86; rectifier is a Haltron EZ80.
Still haven't heard it right, need to change the circuit a bit, first.
As usual in my amps, all the iron is custom made by Edonion
Hey!
Here's my newest offspring, a winged-C 6B4G SE amp, pre-amp stage is an winged-C EF86; rectifier is a Haltron EZ80.
Still haven't heard it right, need to change the circuit a bit, first.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
As usual in my amps, all the iron is custom made by Edonion
50EH5
Ack, another 50EH5! Good stuff.
I built mine around the original tube data notes with help from the link you shared above and Dave's http://www.t-linespeakers.org
For more info on my 50EH5, visit my website:
http://ca.geocities.com/gmilitano
Yup, your OTs look larger than mine too. My long term plan is to have them run some Radio Shack 40-1310 super tweeters.
Cheers,
Gio.
philipbarrett said:
Ack, another 50EH5! Good stuff.
I built mine around the original tube data notes with help from the link you shared above and Dave's http://www.t-linespeakers.org
For more info on my 50EH5, visit my website:
http://ca.geocities.com/gmilitano
Yup, your OTs look larger than mine too. My long term plan is to have them run some Radio Shack 40-1310 super tweeters.
Cheers,
Gio.
My RH84 design Amplifier by creator Mr Alex Kitic
http://www.geocities.com/zulmr2/hifi/rh84a.jpg
My Monster 2A3 Amplifier
http://www.geocities.com/zulmr2/hifi/2a3b.jpg
My Clone M10 Preamplifier
http://www.geocities.com/zulmr2/hifi/m10a.jpg
My 6922 Preamplifier
http://www.geocities.com/zulmr2/hifi/imag2830.jpg
All my iron sets are purchased at
Promitheus Audio
http://www.geocities.com/zulmr2/hifi/rh84a.jpg
My Monster 2A3 Amplifier
http://www.geocities.com/zulmr2/hifi/2a3b.jpg
My Clone M10 Preamplifier
http://www.geocities.com/zulmr2/hifi/m10a.jpg
My 6922 Preamplifier
http://www.geocities.com/zulmr2/hifi/imag2830.jpg
All my iron sets are purchased at
Promitheus Audio
