bgrier 🇨🇦 🍁Feb 2, 2025

ADC 1700DD Turntable Restoration - Introduction
First post in a series. Subsequent posts in the replies

Well, made good progress on the ADC 1700DD turntable restoration this weekend. I'll pop a bunch of photos and comment on them in this thread.

First up - It's ALIVE!!

Background - this turntable was part of a system that I picked up at a garage sale last summer. The speakers were all shot (rotten foam surrounds - another project currently on the bench) and this turntable was 'unknown'. Missing its dustcover and paired with a moving coil cartridge that it didn't ship with. But it spun, and being quartz locked, it did lock in at 33⅓ and 45. So it was a start.

#VintageAudio #Turntables #Restoration #Retrotech

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Show threadbgrier 🇨🇦 🍁Feb 2, 2025

ADC 1700DD Turntable Restoration - The Headshell

The headshell - well, this was not the one that was originally paired with the unit when it shipped. What should have been there was this tiny-little LMH-1. I discovered the difference when I was trying to set up the cartridge with an alignment template. No way to make it align properly so that told me that something was fishy with the geometry.

And apparently this design is kinda famous in that it introduced the industry to the low-mass tonearm concept.

#VintageAudio #Turntables #Restoration #ADC #Retrotech

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Show threadbgrier 🇨🇦 🍁Feb 2, 2025

ADC 1700DD Turntable Restoration - Headshell Fix

So in the spirit of restoration, had to find an original headshell. Did, installed, and _poof_ the cartridge alignment went as it should.

But, this headshell and cartridge were so light, there was no way to properly load the stylus to 1.5 grams. I'd never had that experience before but the most weight I could dial in was .5 grams.

#VintageAudio #Turntables #Restoration #Retrotech #CartridgeAlignment

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Show threadbgrier 🇨🇦 🍁

ADC 1700DD Turntable Restoration - The Penny Fix

So, after thinking about it a bit, I did what anyone from my generation would have done. I taped a _penny_ to the headshell :D

Well, not really, but the end result is the same. The first headshell had what I originally thought was a shim. Turns out it was a weight. So I moved it to the new headshell, adjusted the counter-weight, and now had proper stylus loading. You can see it in the close-up photo as the thin black plate sticking out between the headshell and the cartridge.

#VintageAudio #Turntables #Restoration #Retrotech #CartridgeFix

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Feb 2, 2025 at 6:10pmWeb
Show threadbgrier 🇨🇦 🍁Feb 2, 2025

ADC 1700DD Turntable Restoration - The Controls

About these controls - Power / speed knob

The aesthetic seems to be knobs and buttons. There is no power switch, per-se. It's more of a main speed selector.

What's interesting is that there's no indication that it's 'ON' until you move the tonearm over the record. Then the Power light illuminates, and the platter starts spinning. So, select the record speed first. Unit is on, but no power light (yet). Got it.

Nice feature, at the end of the record side, the turntable automatically returns the tonearm to the rest and stops the platter. A feature some modern high-end tables seem to be missing.

#VintageAudio #Turntables #Restoration #Retrotech #AudioControls

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Show threadbgrier 🇨🇦 🍁Feb 2, 2025

ADC 1700DD Turntable Restoration - The Speed Controls

It's all about the speed – Quartz Lock Button and Speed Adjustment

On the left side, we've got this cluster of controls and indicators.

So, you select the record speed when you power on the unit (previous post), but here we can lock it in or tweak it. Interesting feature, but not sure what need it’s fulfilling. Based on a quick test, it looks like you can tweak the speed +/- 10%.

#VintageAudio #Turntables #ADC #Restoration #SpeedControl #Retrotech

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Show threadbgrier 🇨🇦 🍁Feb 2, 2025

ADC 1700DD Turntable Restoration - Time to Use It

Now that it's properly functional, I'll swap out my current turntable and give it a bit of a run. Already I've got some minor things that need attention:

- Unusual rubbing sound from the drive mechanism as the tonearm approaches the end of the record.
- Find a dust cover.
- Find or fabricate additional headshells for the other moving-magnet cartridges I have.

But first, I have other projects on the bench. Speaker surround foam replacement is next.

#VintageAudio #Turntables #ADC #Restoration #Retrotech #SpeakerRepair

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