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Bottlehead Kits => Crack => Topic started by: suttonri on February 14, 2025, 01:03:29 PM

Title: All RCA terminals infinite resistance [resolved]
Post by: suttonri on February 14, 2025, 01:03:29 PM

Hello,

First time kit builder here. All resistances measure OK and then I finally get to the ohm checks at the RCA jacks. The ohm meter registers overlimit on both jacks, hot or ground, regardless of the scale selected. By my eye all the solder joints on the RCAs and volume pot look good.

What do I do next?

Thx,
RS

Title: Re: All RCA terminals infinite resistance
Post by: Paul Birkeland on February 14, 2025, 01:20:13 PM

It would be a good idea to post some build photos first thing.

Title: Re: All RCA terminals infinite resistance
Post by: suttonri on February 15, 2025, 03:05:33 AM

Here ya go!

Thanks,
RS

Title: Re: All RCA terminals infinite resistance
Post by: suttonri on February 15, 2025, 03:19:12 AM

Those photos are MUCH clearer on my phone. How do I get sharp uploads here?

RS

Title: Re: All RCA terminals infinite resistance
Post by: Paul Birkeland on February 15, 2025, 05:16:19 AM

What's the DC resistance between terminal 3 and the center post on the 9 pin socket?

Title: Re: All RCA terminals infinite resistance
Post by: suttonri on February 15, 2025, 07:26:47 AM

Also overlimit. I'm looking forward to learning what this tells you.

Thx, RS

Title: Re: All RCA terminals infinite resistance
Post by: Paul Birkeland on February 15, 2025, 08:16:17 AM

There's a black wire leaving terminal 3 that goes to the volume pot, then from that connection on the volume pot there's a bare jumper that connects the two ground lugs on the volume pot, then another wire leaving there to the center post of the 9 pin socket.

Either there's a missing wire/jumper in that string of connections, or you have a bad solder joint at one of those connections.

Title: Re: All RCA terminals infinite resistance
Post by: suttonri on February 15, 2025, 09:19:26 AM

It was the 3L to lower potentiometer tab closest to the 9 pin socket, as shown on page 35, picture 2. I'm continually amazed by how simple things slip by me. I even walked through the instructions, checking each solder before checking resistances!

I guess the troubleshooting thought process was to keep chasing the circuit upstream from the RCAs until you find a break?

Anyway, thanks a million! On to the voltage checks! I suppose the penalty for screwing up here could be infinitely higher...

RS

Title: Re: All RCA terminals infinite resistance
Post by: Paul Birkeland on February 15, 2025, 10:26:21 AM

The risks of problems during the voltage checks are vastly reduced by passing the resistance checks. 

Title: Re: All RCA terminals infinite resistance
Post by: suttonri on February 16, 2025, 08:15:24 AM

Voltage checks passed and I had a listening session this morning with a Chord  Qutest upstream and Sennheiser HD-800S down. I would be content with this as an endgame headphone system. It will go to my son as a graduation present.

I'm looking forward to adding the Speedball upgrade but for a while I'll enjoy the base model and learn it's characteristics so I can appreciate the Speedball better.

Much thanks for the timely and insightful troubleshooting


RS