Our friends Bruce and Rodney sent a message informing us that their website - OddWattAudio.com is now active and that it should be fully functional in the next few days or so. Some of you will will recognize the term "OddWatt" which is the name Bruce gave to his scalable push-pull amplifier projects. The DIY versions of the OddWatt tube amplifiers are documented on the DIY Audio Projects website and are listed below.
- 5751 SRPP / EL84 SIPP iPod Tube Amplifier
- ECC802S SRPP / EL84 Push-Pull Tube Amp
- 6SL7 SRPP / KT77 Push-Pull Tube Amplifier
- 12SL7 SRPP / KT88 Push-Pull DIY Tube Amp
The OddWatt circuit is failry simple and consists of a SRPP driver stage which feeds a self-inverting push-pull (SIPP) output stage. The output stage operates only in Class-A mode and the bias is set using a LM317HV regulator that is configured as a constant current source (CCS).
Currently OddWattAudio.com is offering KT77 and KT88 OddWatt amplifier kits as mono-blocks. However, their website indicates that stereo EL84 OddWatt kits should be ready around July. The OddWatt site also indicates that a stereo preamplifier and a headphone amplifier kit may be available in the future. Photographs of the KT77 and KT88 tube amp kits are shown below.
Photograph 2: OddWatt - OddBlock KT88 Push-Pull DIY Tube Amplifier Kit Parts
The photos below show a the finished OddWatt KT77 and KT88 tube amplifier kits.
Photograph 3: OddWatt Audio - OddBlock KT77 Push-Pull DIY Tube Amplifier Kit
Photograph 4: OddWatt Audio - OddBlock KT88 Push-Pull DIY Tube Amplifier Kit
The finished mono-block kits look great. Based on the information on the site, the kit comes complete with all the parts required to build the amplifier. I've been meaning to build an OddWatt amplifier for some time now so the timing was good and I placed an order for a pair of KT88 mono-blocks last week. My kits should arrive in the next few days. When they do arrive I'll post an update complete with photographs.
Update (29 September 2009) - OddWatt Tube Amp Kits now available at TubeDepot
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