183 Preamp PCB layout for 1U chassis

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dmoose5835
Posts: 14
Joined: Fri Feb 28, 2020 2:13 am

183 Preamp PCB layout for 1U chassis

Post by dmoose5835 »

Second pass with beefed up +12V rail (1mm/40mils).

Default traces 0.5mm (20mils).

Cheers!
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dmoose5835
Posts: 14
Joined: Fri Feb 28, 2020 2:13 am

1U 183 PCB UPDATED

Post by dmoose5835 »

Traces widened and separation improved.
BOM priced as of 28MAR25 with Mouser and other partnumbers.

You are invited to use or kibbitz if you wish.
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Guy77
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Joined: Sat May 31, 2014 2:46 am
Location: Toronto, Canada

Re: 183 Preamp PCB layout for 1U chassis

Post by Guy77 »

Hi.
I was looking at your board in PCB-Way Gerber viewer.
I wanted to ask if these ( yellow arrow) are screw in terminals for the wires connections to the pre amp tubes for example.
Also what are the dimensions of your preamp board?

Thanks!
Cheers
G
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dmoose5835
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Joined: Fri Feb 28, 2020 2:13 am

Re: 183 Preamp PCB layout for 1U chassis

Post by dmoose5835 »

Guy77 wrote: Sat Mar 29, 2025 3:18 pm Hi.
I was looking at your board in PCB-Way Gerber viewer.
I wanted to ask if these ( yellow arrow) are screw in terminals for the wires connections to the pre amp tubes for example.
Also what are the dimensions of your preamp board?

**
Hey, Guy - those are connectors with a 3.5mm pitch from the Molex Ultrafit line:
538-172286-2103 172286-2103 Molex Headers & Wire Housings ULTRAFIT 3.5MM 3CKT HDR VT SGL K NAT TIN
538-172253-6112 172253-6112 Molex Headers & Wire Housings ULTRA-FIT CRIMP TERM 20-22 30MI Form,
538-172256-4103 172256-4103 Molex Headers & Wire Housings ULTRA-FIT HSG SR 3Ckt White
and so forth.

The header goes in the board, then the wire contacts and housing for that connector plug in.
That should make swapping pots and pre-wiring tube sockets easier.

Of course, you can do that any way you wish.

A not-quite-complete BOM is attached.

The board is 375mm x 130mm. I'm planning on 1/8" board thickness and an ENIG finish, but I have to buy five of them.
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Guy77
Posts: 983
Joined: Sat May 31, 2014 2:46 am
Location: Toronto, Canada

Re: 183 Preamp PCB layout for 1U chassis

Post by Guy77 »

dmoose5835 wrote: Sun Mar 30, 2025 10:38 pm
Guy77 wrote: Sat Mar 29, 2025 3:18 pm Hi.
I was looking at your board in PCB-Way Gerber viewer.
I wanted to ask if these ( yellow arrow) are screw in terminals for the wires connections to the pre amp tubes for example.
Also what are the dimensions of your preamp board?

**
Hey, Guy - those are connectors with a 3.5mm pitch from the Molex Ultrafit line:
538-172286-2103 172286-2103 Molex Headers & Wire Housings ULTRAFIT 3.5MM 3CKT HDR VT SGL K NAT TIN
538-172253-6112 172253-6112 Molex Headers & Wire Housings ULTRA-FIT CRIMP TERM 20-22 30MI Form,
538-172256-4103 172256-4103 Molex Headers & Wire Housings ULTRA-FIT HSG SR 3Ckt White
and so forth.

The header goes in the board, then the wire contacts and housing for that connector plug in.
That should make swapping pots and pre-wiring tube sockets easier.

Of course, you can do that any way you wish.

A not-quite-complete BOM is attached.

The board is 375mm x 130mm. I'm planning on 1/8" board thickness and an ENIG finish, but I have to buy five of them.

Thank you for the detailed information!

Cheers
G
fred.violleau
Posts: 543
Joined: Tue Jun 06, 2017 12:20 pm
Location: Montreal, Canada

Re: 183 Preamp PCB layout for 1U chassis

Post by fred.violleau »

Hey Dmoose5835,

Very interested with your PCBs.
I am switching over to rack preamp builds.
Amp are taking too much space, and Dumble power amp sections re very redundant;
Where do you get your PCBs printed?

Do you have a reference for the connectors on mouser? Never used any of these and dont know how to call these pieces ;)
EDIT : just saw your BOM post, will get through it !
Is it a proven design ?

Thanks for your help!

Fred.
dmoose5835
Posts: 14
Joined: Fri Feb 28, 2020 2:13 am

Re: 183 Preamp PCB layout for 1U chassis

Post by dmoose5835 »

It's NOT a proven design, yet, and have not ordered boards with personal funds yet.

I based the circuit on the MonkeyMatic HotRodDeluxe to ODS conversion PCB - a design that's at least 12 years old.
The topology is pretty constant, so changing the BOMs can shift you among BluesMaster, HRM, Skyline etc variants - and I intend to cook up at least 3 preamps.

I'm also working up a stereo power amp (22W per channel to start).

I don't claim to be a Dumble expert - just starting out on this path. Maybe give me a few months to actually get at least one built before you spend any money on copying me?
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