Parts questions

[Oddvar R]

Hi.

I am about to build a Dumble ODS# 183 and I wonder a bit about some parts that I haven't experienced before and was hoping to get some help here:
1) There seem to be two relays on two separate boards, any advise on what to buy?
2) There is a AMIGO transformer Y048A-006, I use 230v, any advise on what to get here?
3) There are also some rather rare parts, the 330uf/385v Spragues that seem to be hard to come by. Any advise on where to buy those, or alternatives?
4) On the drawing ODS# 183 the pots seem to have rather odd values, are these to be taken literally? (And do they exist?) Like 2.199k?
5) The NTE parts, any retailers for those?

Hope this wasn't to much.

[norburybrook]

1: I always use Omron relays. Make sure you get non polarised ones if you want to save a bit of head scratching if you're following a layout or using the boards listed in the files section. Just choose what voltage you want and get the appropriate regulator.


2: again you need to find a transformer with your 230/240 primary and then something that will give you a ball park figure for your regulator, usually 5v or 12v. I have transformers made with an extra secondary so I don't need to use an auxiliary transformer.

3: https://www.banzaimusic.com/JJ-330uF-385V-radial.html they're radial but if you're making your own board then you can adjust, otherwise try a google search.



4:these are the exact values of the pot on the amp, just get the nearest value. 2.199k is a 2k pot it's within 10% tolerance.

5: Google or try banzia or tube town germany or Modulus amps in the UK..Mouser have a huge stock. RS supplies. Farnel.





MC

[Oddvar R]

Will this be ok?

Omron-G6A-234P-ST15-US-DPDT-PCB-Mount-Relay-12V-dc

[norburybrook]

Will this be ok?

Omron-G6A-234P-ST15-US-DPDT-PCB-Mount-Relay-12V-dc

that will work fine, however it is polarised so you'll have to be aware of that and wire the coil accordingly.

you'll need a 12v regulator with that and a transformer that can deliver above a rectifier 12V.


check out the rectifier board on your build to see if it's a voltage doubler or not. Some Dumbles needed a doubler to get to the 12v for the relays from the transformer used.
I've not made a #183 so can't comment.



MC

[Oddvar R]

Hi and thanks, do you have any not polarised ones?

[donvan]

3: https://www.banzaimusic.com/JJ-330uF-385V-radial.html they're radial but if you're making your own board then you can adjust, otherwise try a google search.
MC

Be aware that this axial capacitor will probably be too tall and will need to lay down on it's side. Since it has terminals instead of leads you are going to have to run wires from the through-hole to the terminals. I hope I am describing this clearly.

I also had to use radial 330uF capacitors and lay them on their sides but I found one with leads that were long enough to reach the through holes - Mouser part# 647-UPT2G331MRD. I also plan to glue mine down with RTV to keep it from vibrating.

I think axial is a better choice if you can find one but I was not able to. If you do, please me know.

[norburybrook]

or put a couple of 220uf's in.

https://www.banzaimusic.com/TAD-AudioCa ... -350V.html or F&T make a 220uf axial as well. its what I've used in all my builds.


I doubt anyone would hear a difference. it might sound better...less stiff



regarding relays they do make non polarised versions. I wasn't aware of the difference and had been using non polarised version then accidentally bought polarised ones and had an afternoon of head scratching working out why they weren't working. had to take the boards out and rewire the relay boards taking into account the orientation of the coils with the diode and the power supply. It doesn't matter if they're not polarised they'll work either way.



MC

[Aurora]

Ad relays.. there are number of manufacturers out there... I use Omron quite a lot also in my work.. unless you specifically want relays with built.in LED indicators, the G5 series is quite suitable for the purpose... https://www.elfadistrelec.no/no/signalr ... &simi=99.9

Otherwise - we may be in the same corner of the world, and I'm about to embark on the same journey.... albeit with a slightly different twist..
I've decided to go with Classic Tone transformers and stick to the well known FIscher&Tausche capacitors..

[Oddvar R]

Interesting, what do you plan to do about the 12v transformer?

[Aurora]

I may use a small toroid for the 12V's, since I'm concidering going with a solid state reverb circuit.....
12V can also be fixed by a voltage doubler from the 6.3 heater....not much power needed just for the relays... there are also lots of good quality 5V relays...

[martin manning]

What reverb circuit are you considering? I’m breadboarding the basic driver and recovery amps from here: http://sound.whsites.net/articles/reverb
Looking to drive a long 4AB3C1B spring tank. Planning on doing some experiments with drive and dwell controls, and mixing of wet and dry.

[norburybrook]

What reverb circuit are you considering? I’m breadboarding the basic driver and recovery amps from here: http://sound.whsites.net/articles/reverb
Looking to drive a long 4AB3C1B spring tank. Planning on doing some experiments with drive and dwell controls, and mixing of wet and dry.

that all looks interesting Martin, keep us posted with your results.


M

[Aurora]

Saw a deisgn that combined two of these with different delay....
http://www.accutronicsreverb.com/main/? ... _05_1.html

[Mr. dB]

Saw a deisgn that combined two of these with different delay....
http://www.accutronicsreverb.com/main/? ... _05_1.html

They need to make one of these with a motion sensor so it still goes "KERBANG!!!!" when you kick the amplifier.

[Oddvar R]

Hi again.

I am going for a standalone 12v transformer, 450mA, but I need it to be 230v ac in. I am having a bit of a trouble finding the right one. Any tips?

There is no reverb on this build, #183.