New DIY V25 Balanced preamp project completed

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mikebarney

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New DIY V25 Balanced preamp project completed
« on: 9 Oct 2018, 06:01 pm »
I've finished up a new balanced preamp using the Morten's V25 LDR boards and OLED display (which is GREAT!).  I added buffers and VU meters to the preamp, details here:
[url]https://sites.google.com/view/tortuga-balanced-preamp/home[url]



SFDude

Re: New DIY V25 Balanced preamp project completed
« Reply #1 on: 9 Oct 2018, 06:09 pm »
Really great job there! Will fit in a lot more old-school style systems with the full width chassis dimensions. :)

poseidonsvoice

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Re: New DIY V25 Balanced preamp project completed
« Reply #2 on: 9 Oct 2018, 06:12 pm »
Great work Mike  :thumb:

Best,
Anand.

charmerci

Re: New DIY V25 Balanced preamp project completed
« Reply #3 on: 9 Oct 2018, 06:12 pm »
Wow.  :bowdown:


Old school VU meters too!


About how many hours did you take to make it?

tortugaranger

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Re: New DIY V25 Balanced preamp project completed
« Reply #4 on: 9 Oct 2018, 06:18 pm »
That's one impressive DIY preamp project Mike. Congrats on a great job!  :thumb:

Cheers,
Morten

mikebarney

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Re: New DIY V25 Balanced preamp project completed
« Reply #5 on: 9 Oct 2018, 06:42 pm »
Morten deserves most of the credit for an incredibly sophisticated design, along with great product support - Thanks very much!
Charmerci: I don't really keep track of build time - I'm a very meticulous (most would say slow-poke) builder.  I designed and built the buffers many months ago.  There was some waiting around time for the chassis and front panel.  But that OLED display really made me want to get it up and running.
Mike

Benny-x

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Re: New DIY V25 Balanced preamp project completed
« Reply #6 on: 15 Feb 2019, 07:39 am »
Mike, that's an amazing job! I followed the full build thread in the link and really like what you did.

I have a question about the addition of the B1 Buffer, though. Why did you add this and what role does it play vs. the existing LDR passive attenuation?

Benny-x

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Re: New DIY V25 Balanced preamp project completed
« Reply #7 on: 29 Dec 2019, 08:39 am »
Hi Mike, I was reviewing your build thread again and have 2 questions I hope you can shed some light on.

#1.
I wondered why it looks like you used each LDR board for R+ and L+ then R- and L- on the other one. and if that's not case, maybe they're configured as R+ and L- and R- and L+? Either way, it seems that you have 1 signal from each channel on each board and I hope htat you ca nclarify a little about that.

#2.
Can you explain how the signal wires are coming off the volume pot? How are you not "dirtying the signal" when the pot should only have 1 "output". Not that I have a solid understanding of this, but it looks like you took 2 leads off the same pot, 1 to the LDR boards and 1 to the buffer boards. Is that right? I get that that might be the whole point of the buffer boards, but I'm kind of learning as I'm going here.

Chilkoot

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Re: New DIY V25 Balanced preamp project completed
« Reply #8 on: 25 Jan 2020, 07:55 pm »
Nicely done!

RDavidson

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Re: New DIY V25 Balanced preamp project completed
« Reply #9 on: 25 Jan 2020, 09:17 pm »
@ Benny-x : Tortuga doesn't use pots whatsoever. That's kind of central to Tortuga's existence and success. Traditional wiper pots are generally awful attenuators especially the more they have to attenuate. Volume control is via the LDR's which are controlled by microprocessor. The external knob is just a multi-controller (encoder) for the microprocessor. None of that is in the signal path.
« Last Edit: 25 Jan 2020, 11:08 pm by RDavidson »

adam2VR

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Re: New DIY V25 Balanced preamp project completed
« Reply #10 on: 18 Mar 2020, 03:30 am »
mikebarney, it's great for sure. But if you will look for some change of audio receiver, I can highly recommend Onkyo TX-SR494 cause it's one of the most powerful receiver I've seen ( found here: https://chooserator.com/best-av-receiver-under-200 ). With a comparison with all other models and options, it's the choice number one for me.
« Last Edit: 20 Mar 2020, 02:35 am by adam2VR »