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[56oval]

Originally Posted by eboz

Mal,

Yep that is exactly what those are. I would say to buy a batch of 10, because at first I had some arc-overs during prototyping. It was probably my own mistake though, because I didn't take as good care for their layout as I should have. There is a max heater to cathode rating that I didn't want to exceed, so I tied the heater to the cathode, in effect making it direct-heated. They're reliable in full wave bridge with heater tied to cathode now, and also make sure to insulate the individual socket contacts well with heat shrink. You see that I used four of these diodes - one each of the others are used in the series with the driver's dual-mono supply just for slow startup and dropping a little voltage. The amp sounds phenomenal, and I would definitely use these diodes again!

And one more tip - if you plan to pair this with high eff speakers >95db and are sensitive to any hum/noise, then I would recommend trying DC heating of the diodes.

Cheers mate ,thanks for the info .

[Nikon1975]

This is a TubelabSE for 45 and 2A3.

Iron is from Silk and it has the possibility to check and adjust bias without opening the chassis.

D.

[Nikon1975]

Pictures did no go through.

D.

[felixx]

Nice.What speakers did you use for them?

[Nikon1975]

The idea is to use it with the microFonken, but up to now I only had the possibility to connect it to the Sonus Faber Grand Piano. It sound good, but not loud for sure.

D.

[felixx]

Sonus Faber Grand Piano............if you want to drive them very good,you need a "welding machine amp" for those.
In case you don't want biamping for your sistem you should try on your local guys to experiment on Maxonic speakers or similar or...a very good back loaded horn type enclosure (Fertin-fullrange speaker or FS speakers).

[AirPower]

My reference Amp, It drive the JBL 4344 very easily. I'm must used 16 caps 560uF/450V in power supply for bass enought strong at full Power output.

Specifications:
- Vacuum Tube Complement:
8 x 3D21WB, 2 x 12SL7 , 2 x 6BX7
- Output Power 90 Wrms (4 Ohms)
10 Hz – 50 kHz ± 3dB (at full power)
- Class of output operation: AB1
- Input Sensitivity / Impedance: 1V / 100K Ohms
- Dimensions W x D x H: 42 x 42 x 21 cm
- Weight per unit: 36 Kg

[firechief]

Air Power -- WOW -- very special workmanship. I presume that you designed the board. That alone is a lot of work.

[mhouston]

Originally Posted by firechief

Air Power -- WOW -- very special workmanship. I presume that you designed the board. That alone is a lot of work.

I'm with this guy. Knockout amp. Makes my SETs look like toys.

[tubelectron]

Hello All,

Any of you have built OTL tube amplifiers ?

Here are my 2 OTL mono blocks (built in 1993) - I hope that the picture will be displayed correctly below :






A+!