Increasing volume pots value - '79 320

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Antoon
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Increasing volume pots value - '79 320

Post by Antoon »

Hello friends,
New to the Rick world and I have bought a 1979 Rick model 320, in which I have installed toaster pickups. I changed the wiring with the fifth knob now acting as a volume/blend control for the middle pickup. With all volume controls all the way up, the output has a total resistance of 100k to ground (2 x 250k + 1 x 500k, in parallel). Now I come from the Fender world and there this would be considered very low for single coil pickups, probably resulting in a relatively dark sound. In a Telecaster this would be at least 250k. Now I would not mind if the 320 would be a bit treblier. Nevertheless I never see anyone upping both 250k volume pots to for instance 500k. Then the resistance to ground would increase to 167k (3 x 500k in parallel), which is more in line with the "typical" single coil pickup load and which would make a lot of difference compared to 100k. Is there any particular reason why Rick players settle on such low vol pot resistances and accept the high end loss? Are their pickups bright enough already? I have a 9k in the neck position, a 7.4k in the middle and a 11.5k in the bridge position with the 5nF strangle cap in line.
Thanks!
Uffingdon
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Re: Increasing volume pots value - '79 320

Post by Uffingdon »

Sorry can’t help with all the technical stuff “as it’s all to fast for little old me” but I fitted one of Dane’s (aceonbass) harness’ with the vintage tone circuit to my 350v63.
With the cap “in” on the bridge pickup and blended with just the right amount of neck pickup (middle p/u all the way down) that’s where the “magic happens” plenty of bite, articulate but with a fullness that for me at least hits the spot.
Before I had the vintage tone circuit I pretty much played on the bridge pickup only, it was ok but it always felt like something was missing.
I will admit though the bridge pickup on its own with the cap “in” sounds well ‘er horrible.
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Antoon
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Re: Increasing volume pots value - '79 320

Post by Antoon »

That 350 is a beauty. You mean you can get it as bright as you want by mixing in any amount of the bridge pickup? I agree that mixing the "Bass" and "Treble" pickup can give really nice sounds when properly balanced. I experimented with that, but sometimes you want the pure sound of the neck pickup only for instance. And that sound is not always bright enough for me.

With 3 pots connected to ground, in parallel, there just seems to be so much treble content lost. But apparently most Rick guitar players do not really mind. That's okay.
Antoon
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Re: Increasing volume pots value - '79 320

Post by Antoon »

I tried my new old Rick 320 with the band (a CCR Tribute band :D ). When playing the whole repertoire I change guitars all the time, depending on what the song needs. But I want each guitar to have roughly the same EQ, so that I don't have to adjust the amp each time. While great sounding on its own, compared to the other two guitars (an LP and a Tele) the Rick has a HUGE amount of bass/low mid and little presence/treble. So I decided to mod the Rick's electronics a bit to make it compatible with the other guitars. First I replaced the two 250k volume pots with 1 Meg linear pots (leaving the 500k middle blend pot in place), which gave (rather unexpectedly) a very useful taper and more treble. Total resistance between the signal and ground increased from the previous 100k to 250k (2 x 1M and 500k in parallel), a more Fender-like value that lets more treble through. A second effect of the higher resistance to ground is that the cutoff frequency of the 4.7nF strangle cap on the bridge pickup decreases, so the bridge pickup becomes fuller sounding because of the higher resistance to ground.
For the extreme bass content of the neck and middle pickup I decided to add strangle caps to those pickup as well, so that I would not have to adjust the amp anymore and having the Rick cut through the band mix better. Quite a drastic move I know. I already tried 6.8nF caps but still way too much bass. So I will experiment further with 4.7nF and 3.3nF caps in series with the neck and middle pickups. The series caps are probably blasphemy to most Rick players as most hate the 4.7nF on the bridge pickup but it just might work for me. I report back on the results..
Antoon
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Re: Increasing volume pots value - '79 320

Post by Antoon »

Did some more testing and ultimately chose 3300pF for the neck and middle pickup and the original 4700pF for the bridge pickup. These values filter enough low end to make the 320 compatible with my other guitars. The 320 still lacks the Fender 'bite' but I consider that part of the sound. I get lots of goodness in return.

The 3300pF between the pickups may seem extreme but note that I increased the resistance to ground from 100k to 250k, an increase of a factor of 2.5, which results in the cap's crossover frequency having decreased by the same factor (1/RC), so the 3300pF would be comparable to 8200nF cap in the conventional circuit.

I also decreased string gauge from 0.012 flat wound set to 0.011 round wound, but with heavier bass strings. I found the 0.012 TI GB strings made the guitar sounding too much like a full scale guitar if you know what I mean (which is not what I am after). There was also too much fundamental in the tone for the Rock music I intend to play with it. I can still intonate the guitar fairly well with the 0.011s but at the same time do all these crazy bends. I can see why John Fogerty used relatively thin strings on his 325.

I am also very happy with the 1M linear volume pots.
Antoon
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Re: Increasing volume pots value - '79 320

Post by Antoon »

And a word about my experience with the Toaster reissue pickups. For this guitar I bought a used set of three Toaster pickups from 1990 that were in a bit of a sorry state. One of them was broken and all three missed most of the corner screws. Two leads were cut short, pole pieces kept falling out. The broken one had so much coil wire on it that the bobbin was too small to hold it. Rick really put as much coil wire on these as they could. The outer part of this coil had fallen off the bobbin and got stuck between the cover and had snapped. After I located the coil break I could unwind that one, to 7.3k, like the new ones. Luckily they are not wax potted.

Most Fender and p90 pickups have about 8000 windings, above or below that is considered over- or underwound. If you recon that the #44 wire that Rick uses has about 1.6 times as much resistance than #42, than the current 7.4k Toasters could be considered underwound. About 8000 windings of #44 on a Toaster pickup would be around 9k, a value not common I think. I was still curious to hear a 9k toaster so I unwound another one to 9.1k. This has turned out to be my favorite one of the three, with the best balance to me. The last one I kept at 11.5k to put in the bridge position.

I had a chance to get a good look at the coil shapes of these 1990 reissue toasters and I am pretty sure these are not machine wound. The winding pattern seemed too irregular for that, as did the coil shape, which was very different on all three pickups. I would say these were wound with a hand-guided wire, just like the current 'scatterwound' toasters.
Antoon
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Re: Increasing volume pots value - '79 320

Post by Antoon »

BTW I tested a few different capacitor types of the same value in the high-pass network and I was stunned to notice the difference in sound between those capacitors. Previously I assumed that any decent film capacitor would do, but after putting a few on an AB switch I noticed big differences in both volume level and EQ. The paper in oil type that I tested sounded much better than the other plastic film types. If you have a high pass capacitor installed and use the bridge pickup a lot, it definitely pays off to experiment with a few different capacitor types.
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