audio-talk

andrew Ivimey wrote:mind you, over there, they've got snow!

Crikey! they are even arguing about it.

Just been and had a look.

Can't see the snow cos I'm an Apple fanboy
but I cannot believe they have started an argument about it. Priceless

Steve

Hi The inside of my version of the DAC does not have the power tank in it, which is probably why the Maplin SMPS makes a difference to the sound on my version. The next version will be the version 3 of the mk6 DAC, which adds the upgraded output stage to the power-tanked spec. Stan Beresford works a...

Not knowing much about this DAC....if you do power it from an Maplin SMPS does this replace the power tank PS that is supposed to be responsible for much of the sound? Sorry, I know little about the DAC so this may be a daft question. Clive Hi Clive As far as I know, the power tank is a very recent...

Hi Steve Just been digging around various forum about the Beresford DAC, noted that the device does seem to polarise opinion. Something I did notice is that some folks are reporting really good results using the Maplin SMPS set for 13.5v - have you given this a go ? Chris :) Yes opinions are quite ...

The Stratmangler wrote:Hi Steve

Are you using the optical or cable connection between SB3 And Beresford ?

Chris

I'm using the coaxial cable connection.

Steve

Well guys We tried the SMPS Maplin power supply on another Squeezebox, this time at Simon's place. Again the improvement was not subtle! so that's 3-0 to Maplin power supplies. Through Simon's system it was also dead easy to hear the positive difference made by the addition of a Beresford DAC, also ...

Thanks Andrew, I'll look into this after Christmas. The idea of one reg per valve on the power stage sounds good. I took the amp to Simon's place today to see how it would fare driving bigger speakers. It was quite good! :D I'd love to hear it on Nick's and Steve's baffles too at some point in the f...

Hi Andrew The whole amp is a fairly low current device The voltage amp driver stage is drawing around 15mA The output stage draws approximately 200mA in total (4 X 50mA) The constant current sinks are sinking 270mA altogether (100mA per output pair plus 35mA each of their own draw via their screen g...

Here is the PSU Driver stage fed by choke input supply, rectified with GZ37 Beam tetrode CCS and output valves fed by 3 section cap input filters Output valves on separate 625VA toroidal transformer Big value caps could mean the PSUs feeding the big valves might be "slow" and treble softne...

I've been simplifying the amp a bit today by taking out the CCS on the first stage 6SL7 voltage amps. Forced into it really after shorting out one of the LM317 regulators to the HT with my meter probe whilst testing voltages in order to do an accurate schematic. Let's just say it made me jump.... an...

This web publication looks quite interesting.

http://www.tonepublications.com/TA-mag.htm

Steve

Yep, I can sign up to that, however in this case as the machine was designed by the operator, maybe its more of a question of reflecting the mind of the builder :-) Well I suppose when the design is your baby, then like Pirsig's narrator's friend John, who couldn't bring himself to fix the dripping...

More tweaking of the driver stage this evening. The 400-0-400 CLC power supply giving 530V to the drivers has been converted to a simple LC setup which has dropped the voltage to 320V. Why do this? Well I began to question the need for a voltage this high, given the reliability problems I have had w...

I did a bit more tweaking of the driver stage today nothing more radical than bumping up the current a tad on the first stage to 1mA, just to lift the loadline up a bit The supply to the 12E14 constant current sinks was finally given snubbing caps around the silicon bridge rectifier which dropped th...

Hi Chris I often wonder what a linear PSU might sound like, but the jump up was so great from the stock PSU to the Maplin switcher that I can't see the improvement being anything other than subtle, if any. I could be wrong though as there has been some real heated debate between the switchers and th...