Talk me out of it! [Super Headless Bass Circuit Modification]
+5
Barry
Westbone
challpa
corsair
Dragondreams
9 posters
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Should I fit a better pre-amp?
Talk me out of it! [Super Headless Bass Circuit Modification]
Hi all.
I have an all original, absolutely as-it-left-the-factory, Super Headless. It is the only instrument I own that has not been modded in some way, even down to the original strap buttons. I'll admit that the strings have been changed a few times (so I can't be a real bass player, right? ). And I've owned this beauty since brand new back in the 80s. My daughters reckon it'll form part of my funeral pyre when they push my corpse into the middle of the local marina in a rowing boat and throw lighted matches at it.
My dilemma is this. Let's be honest - the active pre-amp in this thing is dreadful. The treble boost would peel paint, and the bass boost is too boomy. And it's either/or. There is no way to strike a tonal balance. Don't get me wrong. I adore this bass. It plays like a dream. Other big name basses have been and gone in my life through the years, but this is my constant companion for bringing the thunder.
Should I modify the pre-amp (and by modify, I mean bin it and fit my own - I'm an electronics engineer)? I've asked myself this question so many times over the years. Now I'm in lockdown due to the pandemic I have the time to take this on as a project. Feel free to flame me for my heresy. But should I do it?
If I do, it'll mean being able to ditch the graphic EQ on my pedal board. If I don't, it'll mean I'll probably ask this question again in a few years.
I have an all original, absolutely as-it-left-the-factory, Super Headless. It is the only instrument I own that has not been modded in some way, even down to the original strap buttons. I'll admit that the strings have been changed a few times (so I can't be a real bass player, right? ). And I've owned this beauty since brand new back in the 80s. My daughters reckon it'll form part of my funeral pyre when they push my corpse into the middle of the local marina in a rowing boat and throw lighted matches at it.
My dilemma is this. Let's be honest - the active pre-amp in this thing is dreadful. The treble boost would peel paint, and the bass boost is too boomy. And it's either/or. There is no way to strike a tonal balance. Don't get me wrong. I adore this bass. It plays like a dream. Other big name basses have been and gone in my life through the years, but this is my constant companion for bringing the thunder.
Should I modify the pre-amp (and by modify, I mean bin it and fit my own - I'm an electronics engineer)? I've asked myself this question so many times over the years. Now I'm in lockdown due to the pandemic I have the time to take this on as a project. Feel free to flame me for my heresy. But should I do it?
If I do, it'll mean being able to ditch the graphic EQ on my pedal board. If I don't, it'll mean I'll probably ask this question again in a few years.
Last edited by Barry on Mon Jun 15, 2020 3:35 pm; edited 2 times in total (Reason for editing : Typo)
Re: Talk me out of it! [Super Headless Bass Circuit Modification]
Just hang onto the OEM bits and get stuck into it, mate - everything is reversible and if it makes you play the thing more, then how can it be bad?!?
corsair- Senior Member
- Number of posts : 6352
Age : 65
Location : Mount Hunter, NSW, Australia
Registration date : 2008-04-08
TheGooliusBoozler likes this post
Re: Talk me out of it! [Super Headless Bass Circuit Modification]
Yes I 100% agree with Corsair on this - make it sound great but hang onto the original bits for resale value in the unlikely event that happens
challpa- Financial supporter
- Number of posts : 220
Age : 58
Location : Brisbane Queensland Australia
Registration date : 2008-05-30
Re: Talk me out of it! [Super Headless Bass Circuit Modification]
I build my own.Westbone wrote:Buy a decent bass amp...
Re: Talk me out of it! [Super Headless Bass Circuit Modification]
Corsair's advice is the best way to go. Life's too short to be unhappy with your gear!
_________________
"A little song. A little dance. A little seltzer down your pants." -Chuckles the Clown
GUITARS : https://legend.barryeames.com
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Re: Talk me out of it! [Super Headless Bass Circuit Modification]
Thanks guys.
Work starts this weekend. I've 18 volts to play with, so plenty of headroom. I want to leave the guitar cosmetically unchanged, so will probably look at building something that can sweep the mid range frequencies with the knob on the front and fit some presets to tweak (then forget) to be hidden inside the control cavity to tailor the rest of the spectrum.
Work starts this weekend. I've 18 volts to play with, so plenty of headroom. I want to leave the guitar cosmetically unchanged, so will probably look at building something that can sweep the mid range frequencies with the knob on the front and fit some presets to tweak (then forget) to be hidden inside the control cavity to tailor the rest of the spectrum.
Talk me out of it
Live the dream Sir and make that baby great again. I've dreamed about a super headless.....you are a blessed man. Will drink a cup of Yorshire Gold tea today to you. .
Re: Talk me out of it! [Super Headless Bass Circuit Modification]
Very noice int it?matsumokukuku wrote:...Yorshire Gold tea...
_________________
"A little song. A little dance. A little seltzer down your pants." -Chuckles the Clown
GUITARS : https://legend.barryeames.com
MUSIC/PIX/VIDEOS: https://getback.barryeames.com (including Spectrum ST)
Re: Talk me out of it! [Super Headless Bass Circuit Modification]
I can't get on with the taste of tea personally (tragic, I know) but I keep Yorkshire Gold in stock for my dad and my sis because they won't drink anything else.
I've made a start on pulling this thing apart and now doing a bit of circuit tracing to see how that first toggle is wired for the stacked humbuckers. Until I can see how that switch is configured I can't decide whether it's a coil splitter or a series/parallel selector. Does anyone know the answer? There were no manuals or instructions when I bought this bass. I've always just fiddled with the switch to get the sound nearest to what I wanted. ;-)
I've made a start on pulling this thing apart and now doing a bit of circuit tracing to see how that first toggle is wired for the stacked humbuckers. Until I can see how that switch is configured I can't decide whether it's a coil splitter or a series/parallel selector. Does anyone know the answer? There were no manuals or instructions when I bought this bass. I've always just fiddled with the switch to get the sound nearest to what I wanted. ;-)
Re: Talk me out of it! [Super Headless Bass Circuit Modification]
Dragondreams wrote:or a series/parallel selector.
Re: Talk me out of it! [Super Headless Bass Circuit Modification]
Had a quick look on the website and also catalog scans and its simply listed as "Dual Tone Switch"
challpa- Financial supporter
- Number of posts : 220
Age : 58
Location : Brisbane Queensland Australia
Registration date : 2008-05-30
Re: Talk me out of it! [Super Headless Bass Circuit Modification]
Thanks. That's what I'd found too. A bit vague.challpa wrote:Had a quick look on the website and also catalog scans and its simply listed as "Dual Tone Switch"
Having traced it through, it's a series/parallel switch - and thanks to Westbone for confirming this.
Re: Talk me out of it! [Super Headless Bass Circuit Modification]
I have updated the website entry.
Thanks fellers!
Thanks fellers!
_________________
"A little song. A little dance. A little seltzer down your pants." -Chuckles the Clown
GUITARS : https://legend.barryeames.com
MUSIC/PIX/VIDEOS: https://getback.barryeames.com (including Spectrum ST)
Re: Talk me out of it! [Super Headless Bass Circuit Modification]
Barry wrote:I have updated the website entry.
Thanks fellers!
Re: Talk me out of it! [Super Headless Bass Circuit Modification]
Life got in the way until this afternoon.
Built on breadboard and working nicely. It gives a decent amount of punch in the mid-range (around 400Hz) that I'm happy with.
All that I have to do now is remember where I put my oddments of Veroboard so I can get this thing soldered together and mounted up.
Once it's all in and working I can post a cleaned up version of my hand-drawn scribbles if anyone is interested.
Book Em Danno likes this post
Re: Talk me out of it! [Super Headless Bass Circuit Modification]
Oh, heck yeah!Dragondreams wrote:... I can post a cleaned up version of my hand-drawn scribbles if anyone is interested.
_________________
"A little song. A little dance. A little seltzer down your pants." -Chuckles the Clown
GUITARS : https://legend.barryeames.com
MUSIC/PIX/VIDEOS: https://getback.barryeames.com (including Spectrum ST)
Talk me out of it
I agree with Barry... Any info and help pays off in a long way.... might need it if my 5 string 775 electronics konk out on me. .will toast to you with more Yorkshire gold...
Re: Talk me out of it! [Super Headless Bass Circuit Modification]
Thanks guys. :-)
I had more time on my hands over the weekend and pulled the "Mk1" (mid-boost) circuit out of the bass. It was okay, but having spent some time playing with it, it wasn't quite what I was after. I have a couple of Sire Marcus Miller Jazz Bass clones, and the pre-amps in those are awesome, which kind of set me a benchmark. "Mk2" is now a "proper" two-band EQ with around 15dB of cut and boost at two centre frequencies of 50Hz and 4KHz.
I've had to order a dual concentric pot for the treble and bass cut and boost because I don't want to make an extra hole in the body. The plan is that the volume and tone controls will move to occupy the current tone and boost control positions. What is now the volume control will become a pickup blend control. And the pickup selector switch will come out so I can drop the dual pot in there. This will also allow me to keep the overall "look" of the control layout pretty much as it is. I'm keeping the original parallel/series "tone" switch and the active/passive switch exactly the same.
Work on it has come to a halt until the dual pot arrives, but the circuit is built, tested, and mounted on the control cover in place of the original circuit ready.
I'll post some pics and the drawings for the two different pre-amp schematics once I've fed me and the cats (almost dinner time here in the UK).
I had more time on my hands over the weekend and pulled the "Mk1" (mid-boost) circuit out of the bass. It was okay, but having spent some time playing with it, it wasn't quite what I was after. I have a couple of Sire Marcus Miller Jazz Bass clones, and the pre-amps in those are awesome, which kind of set me a benchmark. "Mk2" is now a "proper" two-band EQ with around 15dB of cut and boost at two centre frequencies of 50Hz and 4KHz.
I've had to order a dual concentric pot for the treble and bass cut and boost because I don't want to make an extra hole in the body. The plan is that the volume and tone controls will move to occupy the current tone and boost control positions. What is now the volume control will become a pickup blend control. And the pickup selector switch will come out so I can drop the dual pot in there. This will also allow me to keep the overall "look" of the control layout pretty much as it is. I'm keeping the original parallel/series "tone" switch and the active/passive switch exactly the same.
Work on it has come to a halt until the dual pot arrives, but the circuit is built, tested, and mounted on the control cover in place of the original circuit ready.
I'll post some pics and the drawings for the two different pre-amp schematics once I've fed me and the cats (almost dinner time here in the UK).
Book Em Danno likes this post
Re: Talk me out of it! [Super Headless Bass Circuit Modification]
I didn't bother drawing out the mid-boost circuit. To be honest, it's not really worth the effort.
The two-band is nothing revolutionary either. It's a simple Baxandall circuit round a dual op-amp. There are loads of similar examples all over the interwebs. I use pretty much the same circuit in one of the models of valve amp I build for customers.
The two-band is nothing revolutionary either. It's a simple Baxandall circuit round a dual op-amp. There are loads of similar examples all over the interwebs. I use pretty much the same circuit in one of the models of valve amp I build for customers.
Re: Talk me out of it! [Super Headless Bass Circuit Modification]
I'm pleased it's coming together with a minimum of fuss, eh... and thank you for drawing out the circuit for us!!
corsair- Senior Member
- Number of posts : 6352
Age : 65
Location : Mount Hunter, NSW, Australia
Registration date : 2008-04-08
Re: Talk me out of it! [Super Headless Bass Circuit Modification]
I have added this info to the Restorations & Modifications section of our website: LINK
(I've also edited the post title so it can be found when searching the forum)
Thanks!
(I've also edited the post title so it can be found when searching the forum)
Thanks!
_________________
"A little song. A little dance. A little seltzer down your pants." -Chuckles the Clown
GUITARS : https://legend.barryeames.com
MUSIC/PIX/VIDEOS: https://getback.barryeames.com (including Spectrum ST)
Re: Talk me out of it! [Super Headless Bass Circuit Modification]
Hi All,
I have a Superheadless and often wondered about installing a different pre-amp (or even removing and using passive-only) as I found it gobbles batteries for fun.
Does the supply rail HAVE to be 18volts, or is it possible to have it at 9volts and have the batteries wired parallel to give longer life?
Can this amp circuit be modified to have a 9v rail, or are there other designs out there?
Thanks
I have a Superheadless and often wondered about installing a different pre-amp (or even removing and using passive-only) as I found it gobbles batteries for fun.
Does the supply rail HAVE to be 18volts, or is it possible to have it at 9volts and have the batteries wired parallel to give longer life?
Can this amp circuit be modified to have a 9v rail, or are there other designs out there?
Thanks
Book Em Danno- Newbie
- Number of posts : 1
Location : Lancashire
Registration date : 2021-01-21
TheGooliusBoozler and Book Em Danno like this post
Re: Talk me out of it! [Super Headless Bass Circuit Modification]
I know they make 18v mods these days. Especially for some of the fenders with coil tap. Also just for a little electrical expertise if you wire it in parallel you don't increase the voltage if you wire it in series you increase the voltage. Parallels great for keeping the voltage the same but increasing the life.
TheGooliusBoozler- Registered Member
- Number of posts : 4
Registration date : 2021-01-07
dongers revenge- Registered Member
- Number of posts : 4
Registration date : 2021-02-02
Re: Talk me out of it! [Super Headless Bass Circuit Modification]
dongers revenge:
You're way off topic and in the wrong forum here my friend!
And you're making multiple posts.
And you're making multiple posts.
Please do not post about a different topic in an existing thread!
You are confusing the discussion.
You are confusing the discussion.
Start a new topic in the appropriate Forum
and ask your question there--thank you!
and ask your question there--thank you!
_________________
"A little song. A little dance. A little seltzer down your pants." -Chuckles the Clown
GUITARS : https://legend.barryeames.com
MUSIC/PIX/VIDEOS: https://getback.barryeames.com (including Spectrum ST)
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