Reviving a seventies bass guitar (1975 Aria A-100)

[1981 LPC]

This thread is in part a copy of a thread in the Tonefreaks/Pickup subsection. It has snowballed so I thought it better to continue it here.

I've been playing bass and guitar off and on for the past 25 years. The short scale P-bass copy (of sorts) pictured below had been sitting in my moms attic for over 20 years. I used it in a band when I was 16 or so (before buying a second-hand Samick Valley Arts bass with active pickups). As you can tell it had, let's call it a "custom paint job".

It's missing the second, smaller pickguard, both tug bars and one pot knob. I don't know what make or model it is. Based on looking at pictures online I would say it's a seventies bass by either Aria, Teisco or Sears. Best guess, I think it's a 1975 Aria A-100. Same pickup, finish, pickguard, knobs, tug bars as seen here in the 1975 Aria catalog: Catalog picture

My seven year old daughter expressed an interest in learning to play. She does have a good ear, so I want to cultivate that. This being a short scale bass, I think it's suitable so I decided to restore it. Well... to fix it up as a father and daughter project.

I took it apart on a Saturday and spent a good many hours scraping and sanding the body. Polyurethane is tough stuff. The body has a multipiece pancake construction - something I absolutely love. It makes for cool looking curves and belly cuts. I did my best to take out dings and other damage, sanding nice curves by hand. Sanding with 120, 280, 400 and 600. Same for the headstock.

I finished both with two thin layers of a clear wipe-on poly, sanding in between coats. My daughter did not want it pink or any other silly colour - she has class and wanted a natural finish. To my surprise we even managed to save the pickguard with the same process of scraping and sanding, and finished it with a rattle-can clear coat. It came out much better than I expected. Partially assembled the acoustic sound is surprisingly nice - round and warm. That's with 25 year old strings....!

 

[1981 LPC]

When I started reviving this old bass I immediately noticed the neck had a big up-bow... because there was no tension on the truss rod. At all. The nut was completely loose... with thanks to my sixteen year old self who knew nothing about set-up and maintenance.

When I tightened the truss rod (with slackened strings) not a whole lot happened. The neck didn't straighten and I only got a 3/4 turn out of the neck rod before the neck started to creak.

Over the past few days my daughter has been really getting into practicing her first bass line, but the big up-bow of course means it plays very badly. Adding insult to injury, there's a set of 50-110 gauge strings on it. Yet she soldiers on.

While waiting on a new set of (40-95 gauge) strings & P-bass wiring kit to arrive, I remembered seeing a Dan Erlewine video where he fixed a neck with the same problem. I tried it today and it worked a charm. The idea is that "By forcing the neck into a straighter (or even back-bowed) position using clamps and a beam/level it’s often possible to then tighten up the truss rod in order to keep it in this position. You’re helping the truss rod by doing the actual neck bending/correction so that little adjustment nut doesn’t have to do all the work. Once it’s snug, the job of keeping the neck there is relatively more easy." Source: hazeguitars.com

I went for the option to force the neck into a back-bowed position. It took two tries but worked reall well. After giving it a initial set-up I was able to get a relief that allows for a credit card to not quite pass under the strings at the 9th fret. It's still not the best playing bass ever but it's a 100% better than it was.

I should mention I also added two extra metal washers to the truss rod nut, so I could get more turns out of it. The wood has probably depressed over the past 50 or so years, this helps with that. Also picked that up from Dan Erliwine. Thanks Dan!

 

[1981 LPC]

Adding to the above, I forced enough back-bow into the neck to be able to sufficiently loosen the truss rod during set-up. That ended up taking 1/2 turn. So I think I now have enough threads to be able to tighten and loosen the truss rod for future use, as changes in wheather and strings give cause to do so.

 

[Roxy13]

Great job!

I have a pancake Aria singlecut from 1979. It's a great playing and sounding guitar but ugly as sin lol. I plan to refinish it this summer.

 

[1981 LPC]

Great job!

I have a pancake Aria singlecut from 1979. It's a great playing and sounding guitar but ugly as sin lol. I plan to refinish it this summer.

Thanks! What's so ugly about your Aria? When you start the project, please show us a few before and after shots.

 

[truckermde]

Hey, that turned out great! Glad you're getting compliance from the truss rod now.

Love a daddy&daughter project!!

 

[Roxy13]

Thanks! What's so ugly about your Aria? When you start the project, please show us a few before and after shots.

It's a particularly ugly shade of clown burst.

 

[1981 LPC]

Moving on to the electrical work. Here's what the back of the pickguard looked like.

The mini volume pot is kaput and there's play in the input jack. At first I wasn't sure if the pickup is a single coil or humbucker type pickup, because of the big pickup housing. The pickup is indeed a single coil, with the ground wire connected to the base plate. I checked its output and it reads between 7.72 and 7.78

I measured the resistance of the mini tone pot. It measures 488K when fully openened which must mean it's a 500K pot. Seems strange, bass guitar with a single coil pickup and 500K pots. I have ordered an Allparts P-Style Bass Wiring Kit
from Thomann. It comes with 2 normal size 250K audiotaper CTS pots.

The simplicity of 1940s technology. Love it. I was glad to have taken off the pickup cover because the magnet was off centre and the coil was tilted to one side...! I fixed them into place with a few pieces of tapered wood (7.8 on the Scale of There I Fixed It).

A thin sheet of rubber to keep the dust out.

 

[Paul46]

Great save. The natural / tort looks fantastic.

 

[1981 LPC]

I received the Allparts P-Style Bass Wiring Kit from Thomann and installed it the same evening. The sound of the bass through headphones is surprisingly good. Warm and responsive. I find the sustain of the bass guitar striking. Not that it is of much use to you as a bass player, but still. I also put new strings on, 40-95 instead of 50-110 - much more suitable for the hands of a seven-year-old. Now find suitable pot knobs ... chicken head pot knobs seem suitable to me.

My soldering work looks like sh@t. I can neatly solder the little tabs on the pots in one go. But I can't solder neatly on the side or on top of the pots. I'm probably not getting them hot enough for the solder to flow nicely, because I'm too careful not heating the pots to the point of damaging them. Wanting to prevent a cold solder joint, I then reheat the solder to make it flow better.

Anyway, I'm not posting a picture of my soldering job but this picture sums it up quite nicely.