Maximum DIY contents in the whole rig and never sounded this good….

[yogibear]

very nice DAC board. do you need lot of gain for this DAC? instead you use tube in the output stage.

Nope. A tube stage to see what it brings. The ensemble could pair well with an SS amp.

 

[yogibear]

I let the dac breaking for a few days and the sound evolved. Tonality is the best I ever heard in my setup regardless of the amplifier used. The dac signal output was beyond my expectations and any amplifier I tried would mate well with excellent gain and drive.

A clip with dac driving a 9 wpc, IT coupled EL84 Push Pull Amplifier: (15% volume level driving 88dB bookshelf speakers)

 

[yogibear]

8th build of the 2025. (Three R2R DAC, one phono and four tube). EL34 SE 20 watts per channel. No feedback. On board meters which help bias unmatched tubes, are mirror to tube and amp health and track that live while the amp plays. Dead silent operation. The arduous task of removing the film from chassis remains.

 

[reignofchaos]

Completed and fired the transformer output coupled DAC today. The digital section is chipless R2R, NOS, no DSP, dual resistor array dedicated to each channel. OPT are very special, Tamura.

Very distinct tonality and presentation with big low end extension. Excellent signal output too. Drives my 300B amps effortlessly.

Next is adding a tube gain stage to it.

View attachment 91095

What is the output impedance of this dac board? Seems like the output is coming straight from the ladder without any form of buffering.

 

[rwnano]

In diy anyone who is good with setting up wireless networks in the house and can give me some feedback? Thank you

 

[yogibear]

What is the output impedance of this dac board? Seems like the output is coming straight from the ladder without any form of buffering.

It uses 1:1 / 600 ohms : 600 ohms OPTs. Yes, the dac execution is very neat and straight forward.

 

[yogibear]

Optimised power supply on the discrete opamp output R2R chipless DAC. Has options for balanced output too. Sounds fantastic. Next are plans to design a case for it.

 

[yogibear]

Latest stint was simpler yet challenging. I decided to brew up a pair of Interconnects using authentic, original nos Western Electric cable. (Encapsulation was a huge challenge as the way I wanted to do it)



The presentation was quite smooth without any loss of details with excellent low end and soundstage. This prompts me to actually use the same cable for all signal paths inside my tube amps and the DAC. That's the way it should be done, right ?

A clip: DIY chipless R2R DAC with discrete opamps connected through WE IC to 6BG6 SE Amplifier. No tone controls or boost. Streaming from Spotify premium.

 

[yogibear]

Next stint: Recreating a DHT Preamp on a larger chassis. It's a line level preamp, simplistic design aimed at maximum sonics extraction out of a DHT tube, and tube rectified using a DHT as well. Sounds musical and dead silent.

 

[yogibear]

Next stint: Apologies, it's not a DIY but only diy content was I inspected the underside carefully for any TLC and thoroughly cleaned all the movable parts / volume controls / selector switches and let it dry for a day.

The amp is Pilot 240 Integrated Amplifier, a piece of American Radio History, all original and no repair history. Tube rectified GZ34, and EL84 PP. Loads of features and options. I chose to play it flat. Sounds silent, powerful, excellent gain, and very very musical. (Would make you reconsider your opinion / impressions about DHT tube amplifiers). 15 watts per channel of dynamic, rich vintage sound, which was all about music enjoyment.

 

[dinesh1201]

what an awesome engineering brain you have!

 

[yogibear]

Next adventure was bringing this legendary amplifier Heathkit W4 AM from years of slumber. Installed a new power cord and improved B plus filtering. All the components under the hood were in perfect health so the originality was maintained. Installed a power switch too. Installed new tubes and it was driven from DHT Preamp.

Sang loud, clear and beautiful and dead silent too. Here is a clip:

 

[yogibear]

Next challenge was to convert an EL84 SE Amplifier to a power amplifier, that is to remove the volume control entirely. With tube amps it's a kind of a challenge, to do so, preserving the voicing, frequency bandwidth loss and make sure the amp still plays silent. Was able to pull this off.

The video clip says it all. The DHT preamp drives the EL84 amp: