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Hoffman Amps Forum image Author Topic: Gretsch 5120 Tweaks  (Read 8395 times)

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Offline HotBluePlates

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Gretsch 5120 Tweaks
« on: February 25, 2013, 01:41:24 pm »
So after learning some basic Chet stuff and playing my homebrew Tele through the 25L15, I had to concede you need a Gretsch (or at least Filtertrons) if you want to replicate the Chet sound.

Bought a relatively cheap Gretsch 5120 (their Korean-made inexpensive alternative to the 6120), but while it sounds more-right the pickups are a bit too muddy in my opinion.

So I sprang for a TV Jones Supertron for the neck and a TV Classic Plus for the bridge.

Why that pairing? Because it is reported to closely replicate the setup Chet had on his 1959 Gretsch (left in the picture), and a number of players on the Chetboard have responded to this set positively. Chet's longtime sideman Paul Yandell convinced Gretsch to duplicate his one-off setup in their 6122-1959 model.

I'm also gonna be replacing the stock tune-o-matic bridge with a Tru-Arc bar bridge. Aside from any tonal improvement, I just like the idea of having the strings glide over a smooth surface when using the Bigsby bar. Audio clips by Craig Dobbins.

So I guess now I'll have to record some sound clips of the 25L15 along with the 5120 like I keep threatening to do. I think it'll be instructive to see what changes and how much.

I also noticed the 5120, even in its stock form sounded much more like Chet through my 25L15 than through the modern Fender-style amps at the shop (which were mostly Hot Rod Deluxes and other amps that weren't a good fit for the sound I'm after). And while my modded 25L15 is kinda zingy with single-coils if I'm not using the Cut control to tame the sound, the somewhat muddy stock 5120 pickups don't need the Cut at all. I'm interested to see how the TV Jones pickups sound...

Offline HotBluePlates

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Re: Gretsch 5120 Tweaks
« Reply #1 on: March 02, 2013, 02:50:26 pm »
Oh yeah... if anyone runs across a gold-colored Gretsch pickguard, either "Nashville" or "Chet Atkins" signpost type, for a good price, give me a head's up.

I'm also gonna be re-tooling the various hardware bits on this 5120, and the prices I've seen for this hunk of plastic are obscene.

I'm also gonna spring for a Chet-style wire-arm Bigsby.

You might think I'm going crazy with replacing much of the stuff on this guitar (and I am replacing a lot...), but even after all of it this will still cost about half what a new Gretsch runs. Too bad their aren't really any players around me selling a used U.S. Gretsch (for a price I can afford).

Offline HotBluePlates

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Re: Gretsch 5120 Tweaks
« Reply #2 on: March 04, 2013, 10:37:24 pm »
Alright, so here are some sound clips of the guitar before changes.

Clips begin with the opening of Wildwood Flower, to allow you to hear each pickup setting. All volumes and tone control are up full.

Recording Notes:
-  All tracks are dry and essentially unprocessed. Each track was normalized to eliminate volume differences which might alter your impression (the bridge pickup alone is actually a bit quieter than the neck pickup). No compression, no reverb, no EQ.
-  I used my 25L15 amp, volume at 2.5, Bass and Treble at 4, Contour set for stock midrange notch frequency, Mid control set for stock maximum mid-dip and the Cut control off (not affecting the circuit). This is basically as close to the stock 25L15 as you can get without using a stock, old 25L15.
-  I used a Golden Age Project TC-1 large diaphragm condenser (kind of a cheapo AKG C-12) 9" from the grill and off-center of the cone into a Focusrite Sapphire 6 interface directly to my computer. I tried a MXL R144 ribbon at first, but it was just too muddy (it might have been better if I wasn't in my living room, could place the mic at some distance and turn up the amp to compensate for the resulting lowered output).

Wildwood Flower - Neck

Wildwood Flower - Both

Wildwood Flower - Bridge

I also recorded 2 other songs, the first half of Jiffy Jam and all of Maybelle. I noticed on Jiffy Jam, which mixes open and fretted notes throughout to play the melody, that open strings sounded almost non-existent. Now maybe the pickups could have been slightly adjusted to help with that, but I have a feeling the original plastic nut is contributing to the lost open string sounds. Good thing I've already roughed-in a bone nut for this guitar.

Also, apologies for bombing the last bridge and some of the outro of Maybelle. I'll do it better next time around.

Jiffy Jam - Both

Maybelle - Both

Now granted, some compression, eq and a touch of reverb would have resulted in basically good recordings (botched notes aside). But I noticed the stock bridge base radius doesn't match the top's radius (meaning some loss of sound transfer), the plastic nut almost certainly isn't helping open strings, the Gretsch-style humbuckers don't have the real "Filtertron" sound. I think if the guitar was 100% tonally that there would be much less correction needed after recording.

I also noticed on the long decays in Wildwood Flower that there is a dissonant resonance that happens at the very tail end of the clips. At first I thought this might be the length of string between the bridge saddles and the Bigsby, but muting those with my palm didn't kill the dissonance. I'm thinking now that sound was being caused by the pot-metal adjustomatic bridge.

I had previously noticed a buzz while playing acoustically that is stopped if I press a finger against the bridge on the saddle adjustment screws. I don't think that really comes through in the sound fed to the amp, although it may contribute a little fuzziness to the notes. That will probably be eliminated by the new bar bridge coming.

So now time for your vote... It's probably more scientific to do just one change at a time and re-record. So I'll let you tell me after what changes I should do a new set of samples.

I'll be replacing the nut with a bone nut, swapping pickups for TV Jones models, replacing the complete wiring harness (for reliability, not tone), changing the bridge to a bar bridge, and swapping the stock Bigsby for a U.S. model Bigsby with a Chet-style wire arm. I'd only expect tonal changes from the changed bridge, nut and pickups.

Offline jjasilli

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Re: Gretsch 5120 Tweaks
« Reply #3 on: March 06, 2013, 08:18:39 pm »
This project sounds like a great concept. 

The guitar sounds good now.  The first few bars of Wildwood Flower could pass as an electric piano, which is pretty amazing!  I particularly like Maybelle.  Nice playing.

Am awaiting "after" sound clips.

Offline HotBluePlates

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Re: Gretsch 5120 Tweaks
« Reply #4 on: March 06, 2013, 10:32:38 pm »
I've started the re-fit of bridge base to the body. Basically taping sandpaper to the top of the guitar, and using it as a radiused sanding block to shape the bottom of the bridge base. That procedure is about 90% done.

I think I'll re-record after getting the bridge base 100% and installing the new nut. In any event, my bridge is taking a bit of extra time getting here and one of the pickups is backordered, so I guess I have the time to make new samples.

I'll also have to work in some time to make myself a little template to create the new wiring harness.

Offline HotBluePlates

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Re: Gretsch 5120 Tweaks
« Reply #5 on: March 10, 2013, 09:48:06 am »
Bridge base refit is done, and a new bone nut installed. The fuzziness in the tone when played acoustically is gone, all notes have much more body and volume, and the open strings seem to me to be ringing clearly.

I did install a set of 11's, because the 10's on it from the store felt too slinky and didn't have the back=pressure I feel helps some fingerstyle licks ring out. While there is likely an impact from using the bigger strings, I got nowhere near the same change when I put 11's on my Strat and 12's on my Tele.

In fact, you can see for yourself that the original plastic nut was hollow inside, and probably accounts for why open strings sounded very muted compared to fretted notes in the earlier sound clips.

I also took the opportunity to install the Chet-style wire arm and make a template for the new wiring harness. So now it's just a waiting game under all my backordered stuff shows up.

Okay, so now a few pics. Overall shot of the guitar as it started, the plastic nut and new bone nut. It doesn't show in the pics, but the bone nut is nicely polished and reflects light (dunno why the camera didn't capture any of that).

Offline HotBluePlates

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Re: Gretsch 5120 Tweaks
« Reply #6 on: March 11, 2013, 11:00:38 am »
So I re-recorded all the sound samples after installing the new nut and fitting the bridge base to the guitar top properly.

The acoustic volume is very much louder than it was before, and the guitar sounds more "solid". However, the recorded sound from the pickups didn't really change that much. So I guess I'll wait until we get the new bridge and pickups here. I'll record some samples with the new pickups first, then add the new bridge and re-record.

Offline jjasilli

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Re: Gretsch 5120 Tweaks
« Reply #7 on: March 11, 2013, 02:23:57 pm »
Great nut job.  Looks very professional!  Surprised to hear there's little change in amplified tone.

Offline HotBluePlates

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Re: Gretsch 5120 Tweaks
« Reply #8 on: March 11, 2013, 05:32:08 pm »
When listening back through headphones, I didn't get a sense of any great change in treble/bass content.

That said, there may be a sustain difference, but I don't know if it would be obvious in the sound samples I initially recorded (except the tail fadeout). When I said the acoustic volume is louder, it's a lot louder, and I can feel the notes vibrating in the neck now.

It makes me wonder if the pickups themselves color the sound enough that guitar changes don't come through. I'm sure you've played amps where every guitar sounds essentially the same; I wonder if these pickups behave that way.

Offline HotBluePlates

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Re: Gretsch 5120 Tweaks
« Reply #9 on: March 24, 2013, 09:54:37 am »
After much delay from backorders, I finally have this project done! Got the bridge at the beginning of the week, pickups by mid-week, and had to wait for the weekend to get them installed.

Replacing the whole wiring harness and installing new pickups is a chore on a hollowbody, so imagine how disappointed I was when I plugged in and it didn't work!  :l2: The wire in the harness is like that used by Gibson or on a Fender Reverb cable: bare braided shield over an insulated conductor. Quick check with the ohmmeter showed a short from hot to ground. Assuming operator error, I un-installed the whole harness...

Turns out I had 2 types of this cable. The first type is the braid over push-back cloth insulation for the hot conductor, the second type has plastic insulation. Because I had used some of Gibson's wiring tricks for soldering the braid directly to ground terminals for the jack and pots and had used the wire with plastic insulation, I found 2 shorts from braid to hot in the cable itself.

New harness with the cable with cloth insulation, and everything worked exactly as it should.

I did rush ahead and use the new bridge to help install the pickups. The old Electromatic pickup mounting rings don't match the new Gretsch-style rings from TV Jones, so all the old holes had to be filled so I could drill for the new rings. I needed the new bridge to hold the high and low E strings to get the proper pickup alignment.

Anyway, with the new TV Jones pickups and the Tru-Arc bridge, this is a different guitar! I mean, the pairing of the 25L15 with the Supertron and TV Classic Plus is magic sprinkled with fairy dust!

So I've been digging on the guitar, but I know the Tru-Arc is making a major contribution because again the unamplified sound is changed for the better. So it's gonna take a bit to do, but I'll have to reinstall the old bridge for some sound samples (so you hear only the change of the pickups), then put the new bridge back in so we get samples showing that change.

In case anyone else considers the Tru-Arc: you'll need a US Gretsch bridge base. These have a wider spacing between the bridge mounting posts, and the US bridges won't fit on the base that comes on the Electromatic. Not surprising, because everything on the guitar was metric. The good news for me was the new bridge base had exactly the right radius to fit the top; the original base that came on the guitar didn't, and had to be hand-fitted.
« Last Edit: March 25, 2013, 02:53:20 pm by HotBluePlates »

Offline jjasilli

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Re: Gretsch 5120 Tweaks
« Reply #10 on: March 25, 2013, 01:14:47 pm »
 :m11

 


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