2006 vintage upgrade?

Faudrei has spotted the right resistors - the only two larger ones on the board. They are roughly in line with one another in the direction of the length of the board and their location is between the op-amp section and the transistor section. I'll try and find a picture.

The original type was a carbon film sourced from Radio Spares in the 80s. I had over ordered and still had a few thousand on stock when the Solo came into being.

It then changed to Welwyn 0.75 watt MFR5 and I think that's the type fitted in the 2007.

We recently discovered more stock of the carbon film Radio Spares ones (I hadn't realised John had re-ordered a load of the RoHS compatible ones) and will be using these up as well - I can't tell any sonic difference between them and the Welwyn metal films. The problem is now that Welwyn are "subbing" out manufacture having closed their UK facility and I can't stand the sound of the new Welwyns.

The only other option seems to be the Brazilian Philips resistors which are now Vishay Sfernice. I have to strike a balance between what I want to hear and what I can afford: I have to buy tens of thousands of resistors a month and so the finicky or speciality audio resistors offered at out of this world prices are out - we'd really have to pump our prices up to cover the cost and that's the last thing I would want to do. My test of a good resistor is its effect on instrumental decay - the "new" Welwyns came to a full stop whereas the old ones held on to the natural decay right to the release - so they did music.

I'd go for the Vishay Sfernice - the good old Welwyns will be like rocking horse sh*t by now (rare).

Digikey or Newark should have them

The only way to tell the old Welwyns from the new Welwyns is to listen to piano note decay and release - if it releases early they're the new ones.


Edited by Graham Slee - 14 Aug 2009 at 6:31pm

mrarroyo wrote: Would this work?: http://www.newark.com/welwyn/mfr5-120r-1/resistor-0-75w-1-120r/dp/97K4948

It says it's a Farnell UK direct ship which could suggest they're the new ones from A.N Other resistor Co.

If anything like the smaller MFR4's, I bought up all Farnell's remaining original ones months ago, so maybe somebody bought up all the old MFR5's?

Better to go for the Vishay.

Or a bog standard 0.5W carbon film.

Or sit tight and wait for the Solo SRGII....

(yes, I know it's taking some time, but I don't want to be doing any more tweaking on it this year if I can help it and I'm just making sure it plays everything in my collection perfectly... well, not quite, it would take till 2011...)