AD Audio

13/05/2021

Here’s a review of recent build of a DDDAC with two DAC boards, valve output stage and built in RPI4 streamer. Inputs were optical, AES, SPDIF and USB and outputs were phono and XLR /AES. It …

13/05/2021

Front view of DAC

12/12/2019

I haven't had a pair of these to renovate for a few months until these arrived. They are in beautiful condition and just needed upgrading to bring them up to scratch. In went my custom crossovers, a Scanspeak tweeter, a Peerless mid range and plenty of elbow grease. As before the result is speakers that sound stupidly good. They are not shamed either… [ 31 more words ]

I haven’t had a pair of these to renovate for a few months until these arrived. They are in beautiful condition and just needed upgrading to bring them up to scratch. In went my custom crosso…

11/10/2019

And suddenly it's raining Tube Technology products as a Unisis came along for a general overhaul. This one had some war wounds along the way: a few burnt resistors had been replaced, a short on the circuit board had been badly patched and the bias pots were working intermittently. The volume pot was noisy and the selector switch was also replaced for good measure. [ 108 more words ]

And suddenly it’s raining Tube Technology products as a Unisis came along for a general overhaul. This one had some war wounds along the way: a few burnt resistors had been replaced, a short …

11/10/2019

This interesting phono stage, MAC meaning Magnet and Coil, came into the workshop for some tender loving care. Nothing too serious, a recap, and some new valve sockets. On testing there's an adjustment to vary the HT voltage which was a bit high. As soon as I moved this to lower the HT, poom, bang went the regulating transistor which also took out a couple of Zeners. [ 38 more words ]

This interesting phono stage, MAC meaning Magnet and Coil, came into the workshop for some tender loving care. Nothing too serious, a recap, and some new valve sockets. On testing there’s an …

31/03/2019

This mega size amp is in for repairs. The fuse has exploded and the bias has failed.

This mega size amp is in for repairs. The fuse has exploded and the bias has failed.

31/03/2019

It looks simple but these valve output stages really bring my DACs to life. This one is destined for the latest DAC to roll off the production line. It's a two DAC board version with valve output stage and special Audyn caps.

It looks simple but these valve output stages really bring my DACs to life. This one is destined for the latest DAC to roll off the production line. It’s a two DAC board version with valve ou…

21/03/2019

Below you can see the valve output stage for my latest DAC build. This is a two board version of the DDDac, with valve output stage and custom power supplies. These sound very special with their Audyn Coupling caps.

Below you can see the valve output stage for my latest DAC build. This is a two board version of the DDDac, with valve output stage and custom power supplies. These sound very special with their Au…

05/03/2019

Yet another AI500 in the workshop. This time for new signal valve sockets along with a recap. The volume pot and select switch were replaced and the switch and balance controls were bypassed. These amps really do represent excellent sound per pound-particularly the early ones-and there are many tweaks for improving the sound quality.

Yet another AI500 in the workshop. This time for a recap and new signal valve sockets along with a recap. The volume pot and select switch were replaced and the switch and balance controls were byp…

05/03/2019

One of these interesting amps came in for repairs and renovations. A polyester cap had shorted in the phono stage, taking out an anode resistor. In addition the amp was recapped, and had a new selector switch and new output valves fitted. I'm always surprised how good these amps sound. The four valves inside are the pre and phono stages, the latter of which seems to be based on the old Marantz circuit. The main large power supply caps seem to have incredibly long life and I've never found any in need of replacement.

One of these interesting amps came in for repairs and renovations. A polyester cap had shorted in the phono stage, taking out an anode resistor. In addition the amp was recapped, and had a new sele…