Pioneer PL-990: You can add a PreAmp bypass Switch

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danm5000
Posts: 4
Joined: 15 Jul 2010 13:58
Location: Vermont, USA

Pioneer PL-990: You can add a PreAmp bypass Switch

Post by danm5000 » 14 Feb 2016 23:39

You can add a PreAmp bypass switch to the Pioneer PL-990.

Whether you want to or need to is an entirely different question.

A colleague gave me a Pioneer PL-990. Its internal amplifier is based on TI-DRV602.

I thought that this Pioneer PL-990 would be perfect to satisfy the out of the blue recent request from my 16-yo wanna-be hipster daughter: "Dad do you have an extra turntable that I can have in my bedroom?" Sure I do have one, and even more so now! Believe me, there is a LOT more to that story.

Anyway, while doing basic research on this model online I came across some recurring themes:

1. This model has a built-in preamplifier.
2. This model does NOT have a switch to bypass the built-in preamplier.
3. This model CANNOT be fitted with a switch to bypass the built-in preamplier.
4. This model isn't a particularly good turntable, but it isn't a spectacularly bad one either.

All of the above came with various side-discussions about all kinds of things, as you can imagine.

I was then quite surprised to discover upon opening up my new PL-990 what appeared to be all of the provisions for a PreAmp bypass switch except the actual switch itself.

So... to prove the internet wrong, I added a PreAmp bypass switch to this unit, and took some photos to document the process. In addition to the switch, I had to remove 2 jumpers from the PCB and add 2 jumpers to the PCB.

I can't use this site to share a pdf of the project, but if anybody is curious you can contact me and I will tell you where to find the file.

The attached photo is before/after my switch was installed, it can be done fairly easily if that is what you want.
2016_02_yy1-001.jpg
Some photos of the project, ask for more details.
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avelec
Posts: 1
Joined: 19 Jan 2018 05:58

Re: Pioneer PL-990: You can add a PreAmp bypass Switch

Post by avelec » 19 Jan 2018 21:40

Hi danm5000, can you please point me to the howto pdf for bypassing the preamp on this PL-990. Thanks in advanced! Sam

Woodywood
member
member
Posts: 77
Joined: 06 May 2018 20:53

Re: Pioneer PL-990: You can add a PreAmp bypass Switch

Post by Woodywood » 06 May 2018 21:03

Hope your are still here!
Was wondering if it would be easier to simply disable the amp on the board ; or could you send me the PDFs or link ?
Thank you
Newbie

Yohonis
Posts: 2
Joined: 18 Jun 2018 22:41

Re: Pioneer PL-990: You can add a PreAmp bypass Switch

Post by Yohonis » 18 Jun 2018 22:51

This is awesome! Thanks for making this thread danm5000! I hope I can get my hands on the pdf so I can do this mode.
Cheers,
Yohonis

danm5000
Posts: 4
Joined: 15 Jul 2010 13:58
Location: Vermont, USA

Re: Pioneer PL-990: You can add a PreAmp bypass Switch

Post by danm5000 » 11 Jul 2018 00:00


Yohonis
Posts: 2
Joined: 18 Jun 2018 22:41

Re: Pioneer PL-990: You can add a PreAmp bypass Switch

Post by Yohonis » 11 Jul 2018 00:12

Your instructions worked like a charm. The board on my PL990 was a bit different but with your instructions I was able to get the bypass switched installed. Cheers!

Bohlja84
United States of America
Posts: 1
Joined: 12 Feb 2019 01:53

Re: Pioneer PL-990: You can add a PreAmp bypass Switch

Post by Bohlja84 » 12 Feb 2019 02:01

Can you upload the pdf again. I'm new to this site and would really like to upgrade my pl990 but says the pdf is out of date. Thanks.

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