29 September 2009

OddWatt Tube Amp Kits now at TubeDepot

Update (30 November 2009) - see our review of the DIY KT88 Push-Pull Monoblock Tube Amp Kits.

Bruce and Rodney from OddWattAudio.com sent us an email to let us know that their OddBlock tube amplifier kits are now also available from TubeDepot for $599 (September 2009).

From the TubeDepot OddBlock kit page:
The OddWatt ODDBLOCK amplifier kits... great sounding amps at an affordable price. These all tube, single channel, class "A" amplifier kits are designed to be big in performance without breaking the bank.
Running in pure class "A" operation, and utilizing a constant current source circuit embedded in the Ultra-Linear output stage, once built these amps will comfortably provide the lowest noise, lowest distortion with maximum musical bandwidth. Thus allowing you, the listener to enjoy the music free of interference from the equipment. Hear more of the music and less of the gear.
Each kit comes with a matched pair of JJ KT77 and 1 JAN 5751.

OddBlock KT77 Tube Amp Kit Parts

OddBlock KT77 Tube Amp Kit
As can be seen from the photos, this is a complete tube amplifier kit which include a nice powder coated enclosure. For those of you with pets or small children, the enclosure also includes a removable vented top to keep those little paws and hands away from the hot vacuum tubes.

OddBlock KT77 Tube Amp Cover
I put together a pair of the OddBlock kits and have been enjoying them for about a month now. The tube compliment on my set is JAN 5751 and Genalex - Gold Lion KT88. I'll get more details of my kit build posted in the near future.

Link to the kits: 5751/KT77 OddBlocks @ TubeDepot

DIY OddWatt Amplifier Projects

What's Playing: Xiomara - Xiomara

08 September 2009

Push-Pull Compactron Amp using TV Tubes

Pete Millett has a new Hi-Fi vacuum tube amplifier project on his website which is refereed to as: The "Engineer's Amplifier" - a distortion canceling push-pull amp using cheap TV tubes (!). The amplifier consists of a 2-stage push-pull pentode design that puts out a little under 20 Watts. The driver stage uses a pair of 6CB6 pentodes in a differential amp configuration with a ICP10M45S CCS. The output stage uses compactron TV sweep tubes (6JN6 or 6JM6 / 6GV5). The output bias is set so that the amp remains in class A1 operation until about 10 watts where it enters class AB1.

6JN6 / 6JM6 / 6GV5 Compactron Push Pull Tube Amp
A solid state power supply comprised of silicon rectifiers and a MOSFET ripple filter with no chokes which helps keeps cost down. The power transformers and audio output transformers are from Edcor who make great quality iron at a reasonable price.

Compactron Push-Pull Hi-Fi Vacuum Tube Amplifier
As you can see, this will not be a simple amplifier to construct using point-to-point techniques. Fortunately Pete is selling printed circuit boards on eBay for $50US (September 2009) - search eBay for "The Engineer's Amplifier" or user: pmillett.

Full details for Pete's latest project the DCPP Amp are available on his website.

More Push-Pull Tube Amplifier Projects:
What's Playing: The Coryells - Funky Waltz

05 September 2009

High-End Audiophile Headphone Amplifier

Kelvyn Shaw in the UK sent us a note with a link to his latest DIY Audio Project - a High-End Headphone Amplifier. The headphone amp is made using only premium components and built around the National Semiconductor LME49710 high-performance Hi-Fi operational amplifier which is noted as costing 20 times more than your typical op-amp.

DIY High-End Headphone Amplifier PCB
LME49710 Headphone Amplifier
Kelvyn notes that the amplifier "Uses only the finest audiophile quality components that have been carefully selected with no expense spared". Power is supplied through a regulated dual rail power supply using a low noise toroidal transformer. The amplifier is housed in a black anodized aluminum enclosure with a heavy duty clear anodized aluminum front panel. An Alps Blue Velvet potentiometer is used for the volume control.
DIY High-End Headphone Amplifier
LME49710 Headphone Amplifier
DIY Audiophile Headphone Amplifier
Finished LME49710 Headphone Amplifier
From the BOM, the cost of the headphone amplifier is about £163 which is about $265US (4 Sept 2009). This is an advanced DIY project but for those who are are to the challenge, all the necessary information (schematic, BOM, PCB gerber data and enclosure panel drawings) to build one for yourself is available from Kelvyn's website KS Projects - Headphone Amplifier along with several construction photos. Nice work and enjoy your headamp.

More DIY Headphone Amplifier Projects:

What's Playing: Joni Mitchell - Wild Things Run Fast