Oddwatt / Oddblock Builder's Thread

[jazbo8]

The schematic states that all resistors are 1W metal film unless otherwise noted. The voltage rating varies, but I doubt any requires 500V rating, aside from the PSU. When in doubt, please contact Bruce at his website/email.

 

[Oxbox]

The schematic states that all resistors are 1W metal film unless otherwise noted. The voltage rating varies, but I doubt any requires 500V rating, aside from the PSU. When in doubt, please contact Bruce at his website/email.

Thank you Jazbo, this is the advice that got me the answer, an email to Brice yielded a quick reply! Much appreciated Bruce.

Ox

 

[Eslheadphone]

Oddwatt at the BAF

I took my Oddwat to the 2017 BAF and talked to some intresting people. Thanks Bruce for the nice design.

 

[Shef]

I took my Oddwat to the 2017 BAF and talked to some intresting people. Thanks Bruce for the nice design.

Pls, the info and the specs on the mains trafo, looks like I might need a similar one. Tnx.

 

[booangler]

wow I really like the layout!!

I took my Oddwat to the 2017 BAF and talked to some intresting people. Thanks Bruce for the nice design.

 

[booangler]

I took my Oddwat to the 2017 BAF and talked to some intresting people. Thanks Bruce for the nice design.

is your amp dual mono? integrated? I ask as it is not a normal looking OddWatt

 

[Eslheadphone]

The power transformer IA a Antek AS-4T360-400VA 360V at $57.00 . This monster weighs in at 9 lbs.I ordered the CA-400 Steel cover $26.00. It is important to insulate the edge of the cover so it does not touch the chassis as it will cause a short circuit. I used a piece of door edge molding from the automotive store. Dual secondary 360V at .55A along with dual 6.3V at 4A.

 

[Eslheadphone]

The amp is dual mono. The power transformer has dual seconday. It does weigh in at about 33 lbs. Mono Blocks would be easier to move, but I like the looks of the stereo version. Note the Eye Tubes on either side of the heatsink.

 

[Eslheadphone]

the link to the round heatsink I used.
2.000" ROUND - HeatsinkUSA

 

[gideon1990]

Only 57 dollar for that transformer, damn

 

[gofar99]

Hi Eslheadphone, Always nice to hear from a happy diyer. Nice looking build. I personally prefer the mono blocks as they allow for easier placement in my listening room. I am presently working on a variation using 4P1L directly heated pentodes. looking for about 4-5 watts. The tubes are easy to obtain and supposed to be really sweet.

 

[JeffYoung]

Nice looking amp. Of all the photos from BAF, pictures of your amp were the only ones I saved to disk.

(Thanks for posting the link to the heatsink too. That was a real eye-catcher.)

Cheers,
Jeff.

 

[Eslheadphone]

Bilg Blue build

Build Shots of heatsink assembly and chassis wiring.

 

[Eslheadphone]

Custom built power boards for oddwatt

Custom designed power boards for Big Blue

 

[Simply Audio]

I was wondering why 2 x LM317HVT voltage regulator could be used, one on each cathode , thus taking away the need for matched pairs of output tubes .
The 25 ohm POT could remain for final balance ?

 

[jazbo8]

IIRC, that would defeat the Class A design of the Oddwatt.

 

[Eslheadphone]

Of the two output tubes one has its grid driven by the first stage . The other has its grid grounded. The output tube with its grid grounded is driven by its cathode. A separate current source for each cathode would leave only one tube amplifying the signal.At that point we have a single ended amplifier, not a push pull amp. Not only is this amp very simple to build, it sounds surprisingly good.

 

[Simply Audio]

If more conventional driver like a long Tailed Pair was used then 2x LM317HV could still be used to bias each EL84 into class A ?

 

[jazbo8]

Sure, then it would not be an OddWatt and no different from other “conventional” push-pull designs.

 

[mark2020]

EL84 Push Pull Tube Amp Selector Switch

Hi,

I am *very* new to this, and I am trying to make sense of the circuit for the Poddwatt Series 2 Power Supply. Can someone help me understand the 3 LEDs and selector switch portion of this? It reads to me that the switch is just including 1 LED, and hence would have a switch to light one of 3 LEDs?

http://diyaudioprojects.com/Tubes/E...ush-Pull-Valve-Amp-Power-Supply-Schematic.png

Thanks in advance

MArk