Parallel to another project, i am planning an AD1 single ended amp. I would love to hear any suggestions for drive tube and rectifier tube, OPT (3K , 5K primary? other specs? ) I would love to be able to drive it with another triode(RE 604), just 2 stages, and install 2 or 3 inputs on the amp(avoiding a preamp-and excessive gain), if that is possible? Gain not, but energy is what i'm looking for.
Feel free to post your ideas here!
cheers all
Feel free to post your ideas here!
cheers all
Transformers have to be big, hard wiring and soft start are mandatory if you want long useful life.
Lots of ideas in this amp.
Glow in the Dark Audio - Sean Casper Single Ended AD1
Lots of ideas in this amp.
Glow in the Dark Audio - Sean Casper Single Ended AD1
5K OPT and when you use original Telefunken no amorphous core, the combination sounds too bright im my opinion. RE604 have not enough gain, better RS241 or EML30, EML20AM, EML20B
Last edited:
Maybe these graphs on the AD1 are usefull.
Page 233: Loadline for Ra = 2K3 and Va = 250 V.
Page 267: Amounts of distortion (d2, d3, and dtot).
Page 268: Effects on total distortion with an ABC1 as driver.
Page 284: Comparing dtot between push-pull and two paralleled single ended AD1's.
They come from this book (size: 88 MB): https://frank.pocnet.net/sheets/033/suppinfo/Philips_Electronenbuizen_BoekV_1951.pdf
Page 233: Loadline for Ra = 2K3 and Va = 250 V.
Page 267: Amounts of distortion (d2, d3, and dtot).
Page 268: Effects on total distortion with an ABC1 as driver.
Page 284: Comparing dtot between push-pull and two paralleled single ended AD1's.
They come from this book (size: 88 MB): https://frank.pocnet.net/sheets/033/suppinfo/Philips_Electronenbuizen_BoekV_1951.pdf
Attachments
I will be using the EML AD1, but occasionally my original AD1. But i didn't know EML also has driver tubes(triodes?) Maybe about 30v output is needed to drive the AD1 properly.
Cheers!
Why not a pentode like a EF11 to drive the AD1. Siemens used it in many great amps, paired with the EL12.
My data book reads 2.3k for OT primary.
My data book reads 2.3k for OT primary.
Last edited:
Thanks so far for the tips!
Rectifier can be RGN2004 or AZ1, AZ4?
I think i might stick with Nickel cores for the transfos
Rectifier can be RGN2004 or AZ1, AZ4?
I think i might stick with Nickel cores for the transfos
I think you mean the EF12, which indeed was used in many professional amplifiers. The EF11 has vari-mu characteristics. As far as I know it didn't find much use in AF applications.
OK, I stand corrected.
I think that in this radio the EF11 is inside the AVC circuit. That has its pros and cons. In a normal AF amplifier there's no need for AVC. I think that using the EF11 under those circumstances is not the best choice distortion wise.
Do you have an example of the EF11 being used (in an amplifier) without AVC?
I think that in this radio the EF11 is inside the AVC circuit. That has its pros and cons. In a normal AF amplifier there's no need for AVC. I think that using the EF11 under those circumstances is not the best choice distortion wise.
Do you have an example of the EF11 being used (in an amplifier) without AVC?
EML30 HAVE 30 gain and sounds very good. But I use only pentode for driver now. C3m or C3o are really great drivers with very low distortion and Imo more neutral than any triode driver
Treat it like a 2a3 amp as far as I can see, and look at 2a3 circuits or indeed 300b circuits. You would need a triode with a mu of 30 or more or otherwise a pentode as suggested.
You would need a pair of AZ1 in parallel, or if you do 2 mono amps then one for each. I love the AZ1 mesh, maybe the best rectifier of all. But when I used 2 mesh in parallel one would always spark even if I heated the tube first. Not good for the tube, and I had one light up quite dramatically. I don't think the solid plates are prone to this. If you share a love for the AZ1 mesh, which is fairly available, then consider 2 mono amps. In my own 2a3 amp (actually 6C4C) I separate the stages into input and output. The output stage gets a 5U4G or 5Z3 rectifier and the input stage gets the AZ1 mesh. That works great.
If you use a German post tube like C3g or C3m you can keep the whole amp European, which would be a nice tribute to European tube history.
.
You would need a pair of AZ1 in parallel, or if you do 2 mono amps then one for each. I love the AZ1 mesh, maybe the best rectifier of all. But when I used 2 mesh in parallel one would always spark even if I heated the tube first. Not good for the tube, and I had one light up quite dramatically. I don't think the solid plates are prone to this. If you share a love for the AZ1 mesh, which is fairly available, then consider 2 mono amps. In my own 2a3 amp (actually 6C4C) I separate the stages into input and output. The output stage gets a 5U4G or 5Z3 rectifier and the input stage gets the AZ1 mesh. That works great.
If you use a German post tube like C3g or C3m you can keep the whole amp European, which would be a nice tribute to European tube history.
.
Last edited:
Absolutely! thats exactly the idea i had from the beginning. I had a listen to a fabulous sounding (restored) Klangfilm amp a couple of years ago when i was in Japan. The gent was running it with vintage fieldcoil (German?) speakers.
i thought the amp was at least 30 watts, turns out it was barely 5 watts per channel. The amp had multiple inputs and i remember only seeing "big tubes" , i think the preamp tubes were REN something. I heard of the reputation of the C3M and G, but aren't they a bit too miniaturized? Will it be able to put enough energy in the amp? Cheers!
