HiFi Subjectivist ¦ Audio Forum ¦ NVA User Group

The tkd range is excellent, 601 is very good and the 2500 series are one of the best ive used short of very expensive stepped attenuators.

savvypaul wrote: ↑Wed Mar 10, 2021 6:10 pm That will be a better pot than you will find in most £2k amplifiers.

Expensive for a manufacturer, acceptable to a DIYer.

Agreed.

I might try it in my diy system first as I haven't had a volume control in there for about three and a half years See how much it degrades the sound compared to the two welwyn RC55y resistors per channel I have in my potential divider. I am interested to find out.

Been thinking about source selectors and stepped attenuators for my diy effort.

For source selectors the candidates (Hificollective) are Elma 2 pole 6 way at £50, Seiden 2 pole 6 way at a £50 or a TKD 2 pole 6 way at £210 Yes you read that right £210. Must be nuts to even consider it as it's only a bloody source selector. As I only need three inputs then maybe I can get it for half price ? I wish I had only one source because the ultimate in source selection is no bloody switch. Same goes for volume control for that matter

The only other option is a double pole triple throw toggle switch which has a on/on/on configuration. Not sure if they are break before make which is what is needed for a source selector. Gold or silver plated three way toggle switch ?

Then we get on to the expensive bit which is stepped attenuation. Some of the prices are eye watering for the kit and ready built versions. Some of the resistors are very pricey especially the Audionote silver tantalum non magnetic jobbies. Can't afford them. I don't want a kit or ready built for reasons I will explain later so had a look at switches first. One or two pole ? That would mean choosing between stereo and mono. I can't decide yet, still torn in two about that. Do I want two volume controls? Could be handy for any balance problems I suppose but two mono switches cost more than one stereo switch.

Candidates for the switch are Elma 1 or two pole 24 way or Seiden 1 or two pole 23 way. There are others with 30, 34 or 47 volume levels (ways) but I don't want that many and it is more costly. I only need 23 way because I will never need the last seven or eight steps on a standard SA.

So the plan is to find the highest resistor to ground that I will ever need. Currently I have a 10K series resistor in my potential divider and a 768R to ground (welwyn RC55y precision resistors). Just the best ones I had knocking about from bodging Naim and Avondale gear. 768R is a good compromise in sound level for different Cd's. I doubt that I will ever need over 2K in this position depending on how much gain my MC cart and NVA phono board has. Need to test that soon .

2K to ground is about step 16 on a 23 way switch. If that is the loudest I ever need it then what is the point of putting the resistors in the rest of the steps. I will use 2K as the highest value but still use all the 23 steps. I can then cram six or seven more values in to that range and have a volume adjustment which is a bit finer than a 23 way and concentrate on the range I use the most. Seems like a good plan.

So which resistors? The candidates are the Audionote tantalum's, AN tantalum non-magnetic and Charcroft bulk foils. I am going to buy a couple of 10K in each and a couple of 750R in each to see which I like best. Maybe they all sound the same If I end up liking the Charcroft the best then so be it but that will end up being just over £600 for resistors Madness ? Quite possibly, we shall see.

In the meantime I have enough different values of RC55y and Dale RN series resistors to make a half way respectable 14 step attenuator. Just need to buy a switch first. I really would prefer no switches at all in the signal path like I have now (just a potential divider made of 2 resistors per channel soldered together) but this system will be going home one day and for my family to use not just me.

Trying to fix my mig welder is proving to be an exercise in swearing. Fooking thing. Won't grip the welding wire to push it through the hose to the tip. I can see some bodging coming here or just buy a new part but I want to use it now

Duct tape to the rescue

Duct tape did the job, I doubt it will last but I got my welding done Just wrapped some around the rollers that feed the wire into the hose. Lets see how long it lasts before I have to replace the duct tape

I have been wondering if one of these stereo attenuator switches can be cut in half to make two mono switches ?



That would save a bit of money. Two 34 way seiden mono switches are £408 and a stereo 30 way TKD switch is £176. Cut the TKD in half and have two mono TKD for £176 ?

I like the look of them but I can't see me needing 48 steps. I've managed for years with only one step

Bought a couple of shielded EI transformers from a guy on PFM taken from some dead active monitors. 21-0-21V with taps at 15V. Don't think I will be using the taps at 15V. Going to use these for my diy Phono2/3 clone. Should do nicely.