Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: tubenit on July 04, 2015, 11:51:18 am
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OK, here's the story ................ I built a kit guitar and started experimenting with changing the pickups magnets out. So, both of my dual coil humbucking guitars have Alnico 3 in the neck pickup and Alnico 2 in the bridge pickup. It only takes me about 30 min to change out the magnets (now that I've done it a few times). Not that it matters, but after changing the pickups out to this, I learned that Joe Bonamassa has the alnico 3 on his signature Gibson Les Paul.
http://www.mojotone.com/support/kb-pickups/What-is-the-right-pickup-for-me (http://www.mojotone.com/support/kb-pickups/What-is-the-right-pickup-for-me)
http://www2.gibson.com/News-Lifestyle/Features/en-us/Pickup-Joint-Magnets-Decoded.aspx (http://www2.gibson.com/News-Lifestyle/Features/en-us/Pickup-Joint-Magnets-Decoded.aspx)
So, changing the magnets gave me an even clearer and more transparent clean tone in my D'Mars w/5879 OD. But it left the OD a little weaker and slightly anemic sounding in the OD.
I've been reluctant to increase the size of the cathode caps as 5uf seemed to be as high as I could go on the OD channel before it got to sounding too gritty to me.
Well, .............. it turns out that with the pickup magnets changed out that I can increase the cathode cap size on the OD chnnel and it doesn't add grit to the tone. Just more overdrive and VERY smooth to my ears.
So when the guitar had Alnico 5 magnets (which are more mid scooped), I could NOT increase the cathode cap size beyond 5uf before it got gritty and harsh sounding to me. I am thinking this is a result of the mid's being scooped in the pickup by the Alnico 5 magnet.
With the Alnico 2 magnets, I could considerably increase the cathode cap size and instead of adding grit, it added smoothness and more overdrive. I am thinking the OD got smoother (and NOT grittier) because the Alnico 2 and Alnico 3 allow more mids thru
So now the D'Mars has a clearer more transparent clean AND a smoother more harmonic overdrive! No matter what I tried on the OD channel with the Alnico 5 pickup magnets, I could never achieve the smoothness that I am getting now with the Alnico 2 and 3 magnets combined with increasing the OD cathode cap values.
Final comment ............. it is worth the time and effort to try different value cathode caps. There is a sweet spot in cathode cap values.
With respect, Tubenit
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Great insights! Happy 4th!
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thanks for sharing tubenit. :icon_biggrin:
--pete
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Another discovery by the mad amp scientist. :laugh:
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If Tubenit keeps this stuff up, he's going to be accused of innovating. :icon_biggrin:
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Tubenit brings another discovery to building amps. We usually try changing cathode caps and resistors to fine tune a build and often over-look other things like speakers and guitar pick/ups.
Right now I'm fooling with a conversion, trying to cut the brightness a bit and not getting the tone I want to hear. After reading Tubenit's post, I pulled out an SG with P90's and alnico's 2 mags. And the overly brightness was gone.
al
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Really neat insights! I never thought of alnico 5 magnets as mid-scooped but it makes sense.
Always good be reminded that our "instrument" includes everything between the finger tips and the air in front of the speaker.
Cheers,
Chip
P.S. Sometimes experimenting with magnet swaps can fine tune a given guitar for the tone you want
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Ironically, since I first posted this thread ............... I got back yesterday one of my Tele's that has both ceramic and alnico 2 magnets in the pickups. DiMarzio Cruiser (ceramic), DiMarzio Area 61 (Alnico 2) and DiMarzio Fast Track 1 (ceramic).
I could clearly hear the difference in warmth and transparency and smoothness between those pickups. The Area 61 with the Alnico 2 was significantly smoother then either of the other playing thru the overdrive channel.
So, I am now thinking of trying a Area 61 (neck), Cruiser (mid) and then routing out for a dual coil humbucker in bridge with Alnico 3.
With respect, Tubenit
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I don't have yet build a TOS but I have built a DOS circuit in my Bassman head. My observation is that in overdrive mode the amp hates all bright guitars and embraces guitars with a lot of midrange. All bright guitars/pickups make it harsh no matter where the controls are set whereas the midrangey guitars make it sing. Very different to my modded Marshalls which take everything that I throw at them.
Cheers Stephan