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#31
Posted: Thu Nov 29, 2012 10:08 pm
by simon
I reckon it must be a south east thing...
Hadn't forgotten thanks Phil
#32
Posted: Fri Nov 30, 2012 3:11 pm
by Mike H
simon wrote:I'm sure you're right Dave. I'm in two minds to either get a wallwart of unknown provenance, or use a trafo and put it all in one box and use the rectification and filtration on the board. I don't know what a good PS for SS looks like
Depends what you mean by 'good'. You could go nuts and have a full-blown regulated capable of 'X' Amps continuous
For your more simple purposes, spookily similar to a bog cap-input PSU for valves, transformer, silicon bridge rectifier, reservoir cap. The cap problee about 4,700uF would do.
HTH
#33
Posted: Fri Nov 30, 2012 4:39 pm
by ed
Hi Simon
the cheap wallwarts from maplins/ebay etc are good for most things. I've been using the basic telephone charger versions for avr microcomputer power supplies and they all seem to work flawlessly.
They all seem to have periodic spikes between 6 khz and 1 mhz but it's not pervasive. If you use one and it's a bit touchy then just add some cap filtering. I've found it simpler than building from scratch but YMMV.
I have one on the Pass B1 and that works fine with a bit of extra filtering, and I also have one on the CLIO(speaker measurement) outboard reference amp and that works fine without extra filtering.
#34
Posted: Fri Nov 30, 2012 4:58 pm
by simon
Thanks chaps. I bought the amp late last night and got the simple LM317 reg they have too. Under £5 which is a lot for a 317 and a few passive components, but to paraphrase the car insurance ad with Iggy Pop I'm buying time! We shall see.
#35
Posted: Fri Nov 30, 2012 5:10 pm
by Dave the bass
I'll try and measure current at say 19V and 24V DC 'HT' Simon. I've got a 0-30V DC Bench PSU on loan for the weekend that'll do up to 3A.
DTB
#36
Posted: Fri Nov 30, 2012 10:20 pm
by simon
Cheers Dave, I appreciate the effort in the interest of hi fi excellence!
#37
Posted: Sat Dec 01, 2012 5:50 pm
by Dave the bass
Bat-Face has been evicted, I have the project room back.
Right I've replicated a worse case scenario, 4R dummy load on each channel of the amp, driven by a 1kHz sine wave from the sig gen to just before clipping (observed on the scope) at the max DC rail voltage of 24V DC... max current pull for both channels driven is 1.37A.
Howsat.
DTB
#38
Posted: Sat Dec 01, 2012 7:50 pm
by shane
Just out of interest, what does she call you?
#39
Posted: Sat Dec 01, 2012 11:21 pm
by simon
Thanks Dave, you're a gentleman and scholar. A 317 would just about do but I might just stick a 338 in instead.
#40
Posted: Sun Dec 02, 2012 11:05 am
by Dave the bass
shane wrote:Just out of interest, what does she call you?
Fatty.
Ugly.
Minger.
Evil Step-Father.
You want the full list? This could take sometime y'know, we've both had over 18 years of practise at name calling
She was only just 7 when JTS and me 1st met. At 25 she's got very good at retorts!
But... when she wants summat doing or she wants help I suddenly become...
Slim.
Gorgeous
Mummys yummy fella.
The best step-dad in the whole world ever.
Strange eh!
Both kids have an ace sense of humour.
No prob's our-Simon,let me know if you need anymore info.
DTB
#41
Posted: Sun Dec 02, 2012 12:40 pm
by Nick
Simple to try both and use the best sounding, but you may find a simple CRC supply like Pass uses for his amps works out better than a regulated supply, I dont think the device will worry if the voltage is 1v higher or so off load. Use the money saved on the reg on better/more caps.
#42
Posted: Sun Dec 02, 2012 2:04 pm
by Mike H
Yes I wouldn't have thought of a reg for a TDA2050, they're pretty non-fussed about supply variations, going by what I remember from the datasheet