mhouston, I did not modify the amplifier circuit other than making slight value substitutions depending on what parts I could get. The B+ supply after the bridge rectifier is also unchanged from van Waarde's schematic that I worked from. My modifcations involved the delay circuit, fan, use of full-wave bridges, and a simpler heater supply for the sake of convenience.
head1962: I'm not sure if the fan is needed, but I figured with the heat from the heater rectifier (which is bolted to the chassis) and those fat cathode resistors, it couldn't hurt to have a bit of air movement. The chassis does get warm when it runs for a while.
Lingwendil, I'm not too familiar with the "transparency" of an amplifier, but I assume it refers to how little the amp itself colors the sound? If that's the case, this would be the most transparent thing I've listened to in my limited experience with tube amps. The flaws I am aware of in my sound are the result of the equipment feeding this amplifier, and not the amp itself. More experienced ears may or may not think differently, but I read good things about this amp before I built it. Sorry I can't be more specific.
At any rate, I love how my records sound on it. Until now I've never heard an all-tube system on headphones.
Keep in mind though, the only other system I'm really used to is a Dynaco PAS-3 into a modified Magnavox 6V6 power amp running some JBL4301B's. A nice system in my opinion, but by no means close to some of the ones I see on here. I'm a college student, so I don't have the bucks or the time to overhaul the rest of my system just yet.
head1962: I'm not sure if the fan is needed, but I figured with the heat from the heater rectifier (which is bolted to the chassis) and those fat cathode resistors, it couldn't hurt to have a bit of air movement. The chassis does get warm when it runs for a while.
Lingwendil, I'm not too familiar with the "transparency" of an amplifier, but I assume it refers to how little the amp itself colors the sound? If that's the case, this would be the most transparent thing I've listened to in my limited experience with tube amps. The flaws I am aware of in my sound are the result of the equipment feeding this amplifier, and not the amp itself. More experienced ears may or may not think differently, but I read good things about this amp before I built it. Sorry I can't be more specific.
At any rate, I love how my records sound on it. Until now I've never heard an all-tube system on headphones.
Keep in mind though, the only other system I'm really used to is a Dynaco PAS-3 into a modified Magnavox 6V6 power amp running some JBL4301B's. A nice system in my opinion, but by no means close to some of the ones I see on here. I'm a college student, so I don't have the bucks or the time to overhaul the rest of my system just yet.
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Vaska 20PP
~18W sine
Made by my "mentor". I just took the photos
~18W sine
Made by my "mentor". I just took the photos
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.
An externally hosted image should be here but it was not working when we last tested it.
From what i can recall it is a williamson circuit. Don't know o much about the schematic because i'm not into PP designs .
The double triodes are ecc85 and 6n2p. Not sure on this one.
Welcome to the most complete do it yourself guide on the D. T. N. Williamson tube amplifier.
. The double triodes are ecc85 and 6n2p. Not sure on this one.
Welcome to the most complete do it yourself guide on the D. T. N. Williamson tube amplifier.
DHT Line Stage
Hi Vgeorge
Supply works with 6AX4 graetz bridge, the hv are LCLCLC the filaments LCL,
1 transformer for HV and 2 for filament.Linestage works with tube in input followed by an LL1660 in 4:1 and followed by an low impedance Slagle TVC in output.B+ and filament are switchable for use of different tubes.Use of ultrapath capacitor between cathode and interstage.The circuit is an design of Thomas Mayer aka Vinylsavor.The cathode resistor is very special, an bifilar wound resistor wire on wood core and dipped in molten beeswax.
regards Tony
Hi Vgeorge
Supply works with 6AX4 graetz bridge, the hv are LCLCLC the filaments LCL,
1 transformer for HV and 2 for filament.Linestage works with tube in input followed by an LL1660 in 4:1 and followed by an low impedance Slagle TVC in output.B+ and filament are switchable for use of different tubes.Use of ultrapath capacitor between cathode and interstage.The circuit is an design of Thomas Mayer aka Vinylsavor.The cathode resistor is very special, an bifilar wound resistor wire on wood core and dipped in molten beeswax
.regards Tony
Hi Vgeorge
Supply works with 6AX4 graetz bridge, the hv are LCLCLC the filaments LCL,
1 transformer for HV and 2 for filament.Linestage works with tube in input followed by an LL1660 in 4:1 and followed by an low impedance Slagle TVC in output.B+ and filament are switchable for use of different tubes.Use of ultrapath capacitor between cathode and interstage.The circuit is an design of Thomas Mayer aka Vinylsavor.The cathode resistor is very special, an bifilar wound resistor wire on wood core and dipped in molten beeswax
regards Tony
Thanks Tony!
I was trying to understand if it was a resistor or capacitor. I made someting similar for the 26 tube, but with battery bias.
What value is your cathode resistor? You use the same value for 801 and 26?
Excellent work. What are the white caps - motor start? and the yellow one under the bonnet?