Passive Preamp Build

[Pepperamip]

Ive got an idea to build a basic passive preamp with a stepped Attenuator.

Thinkng of having my in and out phonos soldered directly onto the Attenuator (1 in, 2 out) Thoughts??

Narrowed my SA down to a Dale or Valab or even Eizz but can't find out much about those ones (they certainly look the part)

Only amp chassis I can find are from China are there any places closer to home selling them does anyone know?






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[Bigman80]

Ive got an idea to build a basic passive preamp with a stepped Attenuator.

Thinkng of having my in and out phonos soldered directly onto the Attenuator (1 in, 2 out) Thoughts??

Narrowed my SA down to a Dale or Valab or even Eizz but can't find out much about those ones (they certainly look the part)

Only amp chassis I can find are from China are there any places closer to home selling them does anyone know?






Sent from my CLT-L09 using TapatalkBy wired directly, do you mean via a bit of wire? If so, that's the best way to do it.

Eizz use carbon film resistors as far as I know, which are usually 5% tolerance. Should sound nice if they are good quality.

I use a lot of EIZZ parts and they never disappoint me.

Chassis, it's all China mate. Nothing wrong with them though generally. Good prices, just account for taxes etc.

[Lawrence001]

He said soldered directly so I guess no wires.

Isn't there also a grounding (or something) resistor to deal with or does that depend on the topology?

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[Pepperamip]

Thx ollie, strange that there isn't much info around on Eizz are they new to the market?

By wired directly I meant have no rca sockets on the back of the box so have the rca leads soldered directly to the SA and the wires permantly hanging out the back of the preamp.

You get your cases from China don't you. Do you have preferred seller?

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[Pepperamip]

He said soldered directly so I guess no wires.

Isn't there also a grounding (or something) resistor to deal with or does that depend on the topology?

Sent from my POT-LX1 using TapatalkOoo not sure about that maybe someone with more experience can answer that one.

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[Firebottle]

Some of the China suppliers have stock in the UK, for instance search for Douk Audio UK.

[Pepperamip]

Some of the China suppliers have stock in the UK, for instance search for Douk Audio UK.Thx Alan, I'll look into that

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[Bigman80]

Thx ollie, strange that there isn't much info around on Eizz are they new to the market?

By wired directly I meant have no rca sockets on the back of the box so have the rca leads soldered directly to the SA and the wires permantly hanging out the back of the preamp.

You get your cases from China don't you. Do you have preferred seller?

Sent from my CLT-L09 using TapatalkAh I'm with you.

Yes, that's fine.

EIZZ have been around for a while but because they are a predominantly selling in China, they dont get much word of mouth in the UK.

As fo recommended sellers, I've neve had any issue when ordering from Aliexpress.

They guarantee your sale and if you aren't happy, they give you the money back. Very good service too.

[killie99]

Aliexpress are much cheaper than buying on ebay - even after taking VAT and ransom payment to the courier in to account.

[Lawrence001]

Thx ollie, strange that there isn't much info around on Eizz are they new to the market?

By wired directly I meant have no rca sockets on the back of the box so have the rca leads soldered directly to the SA and the wires permantly hanging out the back of the preamp.

You get your cases from China don't you. Do you have preferred seller?

Sent from my CLT-L09 using TapatalkBest sounding solution in theory but don't use a stiff cable as the forces will be too high and make sure the soldering is top notch, strong, and you don't pull on them at all. It would be no good for me with all the tinkering I do, wouldn't last a week [emoji38]

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[Bigman80]

Best sounding solution in theory but don't use a stiff cable as the forces will be too high and make sure the soldering is top notch, strong, and you don't pull on them at all. It would be no good for me with all the tinkering I do, wouldn't last a week [emoji38]

Sent from my POT-LX1 using TapatalkIt made no difference when I tried it but would never dissuade anyone from doing their own experiments.

The biggest factor is the quality of connection. If you get that right then you'll be OK.

Nice little project though.

[Pepperamip]

Was thinking of some kind stress relief where the wire meets the enclosure. Maybe some sort of metal wire I can wind around each of the 6 wires and then attach to the inside of the box out of sight. Something like that anyway.

[walpurgis]

You can get gripping cable glands (a sort of grommet). Or, you can use ordinary grommets and put a small zip-tie round each cable inside the case to stop it pulling through.

[Bigman80]

Was thinking of some kind stress relief where the wire meets the enclosure. Maybe some sort of metal wire I can wind around each of the 6 wires and then attach to the inside of the box out of sight. Something like that anyway.Cable gland.

Very simple and will look fine. If you're using a cable about 8mm, let me know and I'll send you a few.

[Pepperamip]

Thanks all. Got some cable glands.... silver solder..... A dale SA and an Ali Express case on order. Once its arrived I'll start a new build thread with some pics for anyone interested.

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[Bigman80]

Thanks all. Got some cable glands.... silver solder..... A dale SA and an Ali Express case on order. Once its arrived I'll start a new build thread with some pics for anyone interested.

Sent from my CLT-L09 using TapatalkExcellent. Look forward to it.

[Lawrence001]

Ooo not sure about that maybe someone with more experience can answer that one.

Sent from my CLT-L09 using TapatalkI'm talking about the shunt resistor someone else on here will be able to tell you more.

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[Bigman80]

I'm talking about the shunt resistor someone else on here will be able to tell you more.

Sent from my POT-LX1 using TapatalkThere may be a "ground leg" on the SA.

A link to which one you've bought will help.

[Bencat]

Any channce of a link to the case you bought as I am considering making a one in one out little unit but would like it to look okay .

[Pepperamip]

Andrew here's the case I've bought:

https://m.aliexpress.com/item/33043371757.html?pid=808_0000_0109&spm=a2g0n.search-amp.list.33043371757&aff_trace_key=e5eeeef702314c23828da0e4025b6a48-1568485446948-08847-UneMJZVf&aff_platform=msite&m_page_id=8309amp-0YFJx3QBt2XefTYE6k9f1A1568485514370

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