Ampeg AEB-1 Bass: MYSTERY PICKUP or MYSTERY PROBLEM?

[@jamesreed8714]

I am the owner of this bass and you are a MASTER! Thank you so much for your expertise and perseverance. It plays and sounds better then ever.

[@guitar_md]

So thrilled to hear this! It's what I live for. So happy you're enjoying the bass and thanks so much for the kind words!

[@nathanrenault]

Looking at the tailpiece in the higher position (4:48) I imagine all that string tension sideways on the vertical threaded rods, translating into lift on the part that they pass through (which presumably has two or three horizontal screws holding it to the body). Ok if they are stainless steel threaded rods, I guess.

[@sonijam]

I had a Rickenbacker with a similar problem. The A string sounded loud and awesome while the other 3 strings sounded dead and with lower volume.

[@dogchicken]

Underneath the spring steel plate is a magnetic pickup and the excess break angle puts too much pressure on the plate reducing the air gap between the spring steel plate and the magnetic pickup. The spring steel needs to have a gap below it or you have the same effect as if the strings touching the pickup on a P Bass.

[@guitar_md]

Excellent. Thanks so much for the comment! Had no idea about any of this. So spring steel with a gap...very interesting! I'd love to experiment with this myself, it's a fantastic sounding pickup and the test you did also sounds great. And you said it was just a standard P-Bass pickup, correct? I'd love to experiment with a pickup design, as I mentioned in another comment I do make my own pickups and I wonder if making something lower profile (a much shorter pickup, like a pancake) would also work well and be easier to install. Would love to see a picture of video of the design you came up with if possible!

[@dogchicken]

@@guitar_md I used a P Bass pickup because that's what I had on hand. Whenever I get back to that project I want to wind a shorter pickup and figure out some way to add pickup height screws from the back to adjust the air gap. It has pretty even response. I started a couple of scroll bass projects and then got distracted by other projects. The video I posted was a test mule I made out of pine and plywood to test the pickup idea.

[@guitar_md]

@@dogchicken I just updated the video description to include the measurements I got with my LCR meter when plugged into the output jack. I didn't include the clip in this video, but the measurements of the pickup are: DCR...................17.24k Inductance........13.7 Henries Capacitance......107pF Very interesting readings. Of course, the pickup will read differently when it's in the circuit as opposed to removed from the circuit, but those numbers shouldn't be that far off. That's a *very* high inductance, and a very low capacitance for such a high inductance reading. Those specs might be very helpful in designing a replica pickup.

[@broforcefreedom4936]

Your videos are getting better and better Guitar MD!

[@guitar_md]

Thank you! I have a lot more on the way, excited to share more!

[@AZCobraman]

Likely the metal plate has fatigued over the years and the plate and magnet got too close...or possibly were even touching. Relaxing the tension/break angle opened up the gap.

[@guitar_md]

Very interesting. Corroborates what another commenter said. I never saw one of these and didn't know anything about this pickup but that makes perfect sense. Fascinating! The best part is it's a fantastic sounding pickup. Can tap anywhere and everywhere on the headstock, neck, fingerboard, body, and it will come through clear as a bell. Pretty crazy amount of sensitivity and tone in these things.

[@AZCobraman]

I have a buddy who made his own and I've used the idea to make a resonator pickup using a humbucker and a thin washer attached to the underside of the cone. Here's his Ampeg vid kzbin.info/www/bejne/pHbTo2OqZbxmg5I

[@OuchMusic]

If those pickups were designed for gut strings the tension would be entirely less. So decreasing break angle would be the solution by decreasing tension. Side note I want one of these basses so badly

[@guitar_md]

Interesting! And me too. I still think about it once in a while all this time later. I'm currently experimenting with a large piezo disc pickup in the neck pocket, wired with a low impedance, noiseless stacked magnetic pickup in the neck position. Interesting results so far. I'm trying it on a Cozart 12 string Strat, and also an old Hagstrom bass that was ready for the scrap heap. The piezo disc in the neck pocket, by itself, is very trebly/nasally -- but it captures *all* of the microphonic sounds, just like this bass did. You can tap the tuners, tap the body anywhere, pick the strings behind the nut -- and it all comes through clear as a bell. Combining it with the low impedance noiseless neck pickup tames that a bit. You can dial in how much microphonics you want by how much you blend the pickups together. I don't have the wiring figured out. Currently just have it set up as standard Jazz Bass wiring. But very cool stuff. I play direct in most of the time these days, so my audio interface acts as a preamp without needing any battery or anything else. I do have a Triton Audio BigAmp Piezo DI "box" -- but it's the size of a jack. Very cool piece of technology. It runs on phantom power, which most audio interfaces have. But just boosts the signal. I don't notice any major tonal improvements from it. A true DI box with EQ options might be the ticket. My goal was to get a more authentic acoustic tone out of a solidbody electric 12 string. And the neck pocket piezo is only something I've heard of a couple people trying before, Frank Zappa being one of them. Anyway. Interesting stuff. I'd say the neck pocket piezo disc pickup could be worth experimenting with. If I figure out a circuit that actually works really well, I'll let you know. The neck pickup I make is simply a noiseless Fender style pickup, like a noiseless Strat pickup. 500 to 1000 turns of wire on each coil. The noise cancellation is nice. And it does seem to work very well blended with that piezo.

[@OuchMusic]

@@guitar_md I’ve found I like adding piezos into trems because I don’t like the nasally tone with what I pay but in trems you can get a janky reverb sound. My coworker recently did this cool thing too where he put a theramin into his neck position pickup area. It was in a Junior too so he got some great use out of it

[@angelacevedo2112]

thanks for sharing this video.. a look into a nice bass.. yeah I knew right away it was getting choked it needs better strings upright strings are great for these ampegs

[@howdyyuvraj]

I was looking for this issue. I have a similar issue with my ibenez gsr 180. The E, A strings sound perfect but the D and G sound weak. I am looking for ideas.

[@guitar_md]

So in that case it would be a completely different issue as the pickup design is completely differen, but the solution is straightforward: Either adjust the height of the pickup, or replace it. You can verify the Gauss strength of the magnets with a WT10A Teslameter, but most people don't have one of those. So the litmus test is adjusting the height, and even lowering the bass side if you have to, to compensate. If you've got the pickups adjusted so the polepieces are much closer to the D and G than they are to the E and A, and they still sound weak, I'd consider replacing the pickup. It's highly unlikely there's low Gauss strength, I mean *very highly unlikely,* but it is possible, and if you're getting a weak output for that reason, replacing the pickup would be best. First I'd simply try lowering the bass side a bit more so the E and A are a lower volume, then raise up the D and G side, and see if you can get them to balance better that way. 99% of the time that will be a fix. I've measured and wound thousands of pickups and a defective magnet is exceptionally rare. Once in a while you might see an Alnico 2 or 3, with lower magnetic strength, in a pickup that's supposed to be all Alnico 5, which can explain why one or two strings sound so much weaker. But this is exceptionally rare.

[@dogchicken]

Here is a test bass I built to test the pickup design. Sorry about the poor phone recording. kzbin.info/www/bejne/pHbTo2OqZbxmg5I

[@guitar_md]

Awesome! Does it have that same sensitivity where you can tap the neck or body anywhere at all and it comes through the amp/pickup? I was pretty stunned at that when playing that bass though I think I forgot to add that clip to this video. Found an interesting thread here: www.talkbass.com/threads/love-of-ampeg-and-other-scroll-basses-part-2.1044767/ I'd have to see a picture to understand how you did it, but you've got me curious. I wind my own pickups so I'd be curious about having one mounted on top of a spring steel plate like you mentioned here. That sounds great!

[@zackstewart4109]

Roundwounds were almost unheard of while Hull was in charge of the company. I very much doubt he "refused" to put them on.

[@guitar_md]

Could be. Just going by what I read on that website made by someone who claims to be the ultimate authority on these.

[@danielcarlson7516]

Rotosound first introduced roundwound bass strings in 1962 and they were widely known (and used) by 1966, when this bass was introduced.

[@pjmuck]

I used to own an AEB-1. It was the worst sounding bass I ever heard. Like a plasticy "boink" sound. The 2nd version was much improved, adding a magnetic pickup in the sweet spot. Rick Danko played one.

[@guitarman...]

I am a guitartech myself and I agree, this line of work is full of surprises ever so often.....

[@guitar_md]

Right? It's nuts. Never know what you're going to run into next. My friend always says that's what keeps him inspired to keep doing this every day -- always something new. One of my most memorable repairs I've collaborated with him on was a hollowbody we put two dowels into to act as sound posts to keep the top from sinking in (it was sunken around the F holes pretty badly). Sometimes you have to get really creative, and you never know what's gonna come in through that door the next day. Sometimes there's guitars I *wish* never came in...but once you figure it out and get everything to work, it always makes it worth it!