DIY talk

I'm still working on what code I want to use. Kerry's original arduino code from Head Case still works for a simple encoder implementation of the v1. 0 boards after changing a single command. But there are updated versions I can't get to compile yet, and haven't been able to dig into why.

 

At the very least stock up on the required transistors. The other stuff is not so critical.

 

Beezar sells DAC PWBs with surface mount parts. The ICs are challenging.

Beezar PWBs

 

I've seen those and almost ordered several times

 

My "trick" for surface mount IC's. I have a very fine tipped probe, really more of a pick. I grab it with an alligator clip to my DMM, and use it to check for shorts between the IC pins. The tips on normal DMM probes are too fat.
I make sure there are no shorts between any adjacent pins. And wherever possible, I put the pick tip on the top of the ic pin, and put the other probe on the pad to make sure there is contact with the pad.
Takes some time, but worth it to make sure all the connections are ok

 

If it's something with protruding leads I tin one of the pads first and then I position the IC while solder is flowing. Once secured I solder the rest.

I have a hot air workstation though which I like using

 

Collecting parts to build a "sissysit". Class A amp based on Pass designs, with Tokin sits.

Have the tokins, chassis and just ordered cinemag transformers. Need to order boards and parts from zenmod at diyaudio next

Randy

 

It is a great amp, probably my favorite of the builds thus far. read the thread carefully , there were so many amendments it was dizzying - although, you are likely building the V3 version which should reduce the risk of error

enjoy the build ..dB

 

Thanks. Yes I plan to build the V3 one. Haven't ordered board kit yet, but I expect to get that since its the latest.
Like many of the diyaudio threads about popular projects, thread is really long. I've read some of it, guess I should read it while I'm slowly gathering parts for the build. Will order the board kits from zenmod next.
It seems fairly straightforward, but I'm sure there is more to it when you get into actually putting the thing together.

Randy

 

anyone have any experience with these smaller TKD pots?

https://www.hificollective.co.uk/catalog/2cp601-dual-taper-potentiometer-p-7321.html

I would be aiming to replace an ALPS RK097 with something like this. Hoping for better sound and/or less rotational noise on my gamma1.5. From what I can see the foot-print is not quite a perfect match but I might be able to tweak the pins just enough to fit.

 

Alex had used these

Alex had used them in a few builds and they seemed to be comparable to the larger TKD - I personally like TKD pots

I was looking for a supplier recently and couldn't find any , so good to know that HiFiCollective has some in stock.

..dB

 

Would be nice to find a US vendor, but I think I have ordered from them before.

 

Does Canada count? https://www.partsconnexion.com/tkd-potentiomters.html

Very limited stock though, just the 100k detent version available.

 

I’ve used them. I ordered directly from TKD as part of a group buy. I currently have the quad attenuator (not potentiometer) for my balanced amp and I hear no scratchiness.

Haven’t tried to swap an ALPs with it so I don’t know how hard the upgrade is. But I think Pete Millet said one that you could squeeze it in a DIY Butte with some effort.

BTW, from what I remember from ordering from TKD is that there is no minimum but under a certain threshold you pay a 20% premium and there’s a lead time of 3 months. Also payment involved an international wire. Obviously this is something made for manufacturers more or the occasional large purchase.

 

Worth mentioning that the 2CP2511 in my Crack has always been scratchy, from day 1. I tried some Fader Lube recently, and it did nothing. Sometimes scratchiness is due to DC on the pot, sometimes the circuit doesn't like seeing impedances change as the volume pot moves, and sometimes the pot is just plain scratchy.

 

i will say when I first built my amp that I heard a lot of scratchiness but this was due to a huge DC offset. Would have been the same with any pot.

After I fixed this it was fine

 

Anybody use a speaker protection circuit in your amps?

I'm starting to think about adding it to my Sissysit build.

I haven't in the past, but thought it would be add just in case. Was doing a little looking, saw some little boards with relays. Relays open when circuit senses DC.

Randy

 

Yes, the ones @xrk971 makes are some of the best out there .

Not cheap, I used some from Europe that set me back $75 each. So for a tested board at $60 each is a relatively small cost to protect your speakers.

 

TKD in US here: Catalog (percyaudio.com)

 

Thanks for the info. I bought his pocket class a boards a long time ago to build a little balanced amp, but no longer have a use case for it.
Heres a link to the speaker protector in his etsy store:
Link to speaker protector

Little more than I wanted to pay, given I'm cheap, but will probably use it.

Did a little research into advantages of SSR over mech relays, in addition to obvious no moving parts. Read that mech relays might have a problem with a high powered amp, arcing contacts when it opens to shut off power.

The diyaudio store sells a pwb based on a relay, but it turns off input power, so for a class a amp with lots of capacitance would take a little while to turn off, not ideal.
Diyaudio store link

Neurochrome also sells a PWB. But would have to go buy parts and assemble it. Or spend even more for a built board.

Randy