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ADA Preamps => Original MP-1 => Topic started by: Guitar_lamar on January 01, 2014, 08:48:43 AM

Title: Muddy/Mushy bass - HELP!!
Post by: Guitar_lamar on January 01, 2014, 08:48:43 AM
Hey everyone! I just got a ADA MP-1 (again). I missed that killer sound. However, I don't remember that bass being so mushy. I've tried multiple types of tubes and nothing really mattered. I pretty much have to lower the gain so much to clean up/tighten up the bass that it's not usable for rock tones. Is there a component gone bad? Something I can replace??  I have the Bass at 2, Mids at -2, treble at 6 and presence at 8. OD1 at 8, OD2 at 7, master at 5.5.
Tubes: JJ HG in V1 and Electro Harmonix in V2. Playing a ESP horizon with Seymour Duncan JB in the bridge.

Any help would be appreciated!

THANKS!
Title: Re: Muddy/Mushy bass - HELP!!
Post by: Dante on January 01, 2014, 06:32:28 PM
Try pulling that mid down more, like -10. It will probably allow you to turn up that bass a bit.

That said, it sounds like maybe your unit needs to see a doc ( :facepalm: )
Title: Re: Muddy/Mushy bass - HELP!!
Post by: Guitar_lamar on January 01, 2014, 07:08:35 PM
Thanks, I'll give that a shot.A trip to the Docs might be more money then just getting another.  :(
Title: Re: Muddy/Mushy bass - HELP!!
Post by: rnolan on January 01, 2014, 10:46:02 PM
I seem to remember that all my MP1 patches (when I had one) had the mid pull down quite a bit, no less than -4 and typically -6.  What amp and speakers are you using ?  Also speaker box placement may help, If the box is on the floor the bass can couple with the floor and increase the bass (as will putting it in a corner).  Raising it off the floor will de-couple it which "may" help.  Tube wise, I put Boogie STRs in my MP1, they still sound great.  I'm not sure if I'd follow the JJ with an EH, or use an EH at all (kinda higher gain fed into a lower gain tube which doesn't seem like good gain structure).  When I embarked on tube research a while ago the EH tubes were not highly regarded by it's all very subjective.  I settled on the New Sensor Mullard re-issues and love them.  A member of the old board tried them in his MP1 and loved them also (and he tried quite a few different tubes).
Hope you get it sorted  :wave:
Title: Re: Muddy/Mushy bass - HELP!!
Post by: herbyguitar on October 10, 2017, 04:43:09 PM
I had the same issue. I don't remember my ADA being so mushy. I retired it about 12 years ago. Got it out about a week ago. Did the battery mod. Plugged it in and WTF??? Even with the mids pulled out. It still sounds good but the dang thing sounds so loose now. It was never this bad before. What in the world would cause it to do this?
Title: Re: Muddy/Mushy bass - HELP!!
Post by: rnolan on October 12, 2017, 01:22:24 AM
Hey herbyguitar, hard to say, depends what you mean by lose  :dunno: .  My initial thoughts are:
Tubes - they go off over time but with use, not just sitting there.  Anyway a new set of nice tight tubes never hurts and often sorts it out.
Caps - the electrolytic capacitors dry up over time (with or without use) so the MP1 noise mod is well worth doing and tends to "tighten" the unit up
MDRT - this replacement transformer (available from MJMP) really makes a difference.  It makes sense to do the noise mod and MDRT at the same time as, IIRC, the MDRT mod requires some cap changes on the tube board
Rear jack mod - this replaces the front and rear input jacks, the front jack gets the most wear over time and needs to be replaced from time to time.

My friend MikeB did these mods and the unit is now like new, but a bit better from the MDRT.  Tube wise, he's using a Boogie STR (so a JJ) in V1 and a Mullard short plate in V2 (or is it the other way around ?)
Title: Re: Muddy/Mushy bass - HELP!!
Post by: rabidgerry on October 12, 2017, 01:39:21 AM
I thought the bass was always loose, hence why people use a boost of sorts in front like I do on my stock units?

I don't think I could use without a boost to play heavy metal.  Perhaps I could for some songs, but the boost tightens it up big time!

Title: Re: Muddy/Mushy bass - HELP!!
Post by: rnolan on October 12, 2017, 01:58:41 AM
Hey RG, I never noticed the bass being particularly loose when I used MP1, though I scooped the mids allot and they were always -ve, I never boosted them (IIRC you use and get good results with some mid boost, maybe this is compensating for the additional bass boost  :dunno: ), eq is all give and take.. and, in the end, whatever works.  And I wasn't playing much (if any) metal, more just hard rock.
Title: Re: Muddy/Mushy bass - HELP!!
Post by: rabidgerry on October 12, 2017, 03:51:51 AM
RN you're playing very different styles to myself so perhaps you didn't notice a loose low end, but it's something I noticed right away.  MP1 is probably acceptable for hard rock

The extra gain stage totally sorts this issue.  For me I'd call it more "flubby" bass.  And no amount of distortion fixes it.  You need the boost unless you have a 3tm on the MP1.  It adds that extra layer as I call it thickens it up to give more "chunk".  I'm not getting into boost discussion here as it's already discussed on other threads, but I am just saying that my way to tighten up the bass is to have an EQ or OD from my FX pedal on in front.

I never have the mids on my MP1 down anywhere near as low (aren't we anti scooped mids on this board???  :lol:)

Also the volume drop is crazy doing that.  I might try it for a laugh but surely it's thin as f*ck scooping the mids?

Hey RG, I never noticed the bass being particularly loose when I used MP1, though I scooped the mids allot and they were always -ve, I never boosted them (IIRC you use and get good results with some mid boost, maybe this is compensating for the additional bass boost  :dunno: ), eq is all give and take.. and, in the end, whatever works.  And I wasn't playing much (if any) metal, more just hard rock.
  No usually an OD from my Boss GT5 (it's analogue).  Obviously you need to set you patch accordingly.
Title: Re: Muddy/Mushy bass - HELP!!
Post by: herbyguitar on October 12, 2017, 07:02:54 PM
I tried putting a tube screamer in front. I pulled down the gains to about 3 and ran the screamer @ around 75%. I also pulled down the EQs to zero except the mids which I ran @ -4. Ran a parametric in the effects loop set at +3db @ 80hz medium band. -3db @ 3.35khz wide band. +3db @ 4.25khz wide band.... seemed to get me close to where I want to be but still not tight enough for my taste. It's been years since I stopped using the MP1 and I don't recall why but this flubby bass problem may be the reason I retired it...
Title: Re: Muddy/Mushy bass - HELP!!
Post by: rnolan on October 13, 2017, 03:34:10 AM
Hey RG, just looked up my old post where I found a bunch of my 1992 MP1 patches:
  #   Voice OD1  OD2   M   B  M   T  P   Ch D     R
103   DT    3.8   3.4   4.5  9  6   6 10      100  0.0
109   DT    8.5   8.0   8.0  4 -6   0   0      100  0.0
107   DT    3.8   6.5   6.5  9  2   2   4      100  0.0
102   DT    6.0   5.0   5.5  6  4  -2   8      100  0.0
Clean
100   CT    4.8   3.2   7.0  4 -8   6 12        10  1.7
101   CT    4.8   3.6   7.5  4 -8   6 12        10  1.7
Seems I mostly scooped for cleans back then, it's a long time ago.

Hey herbyguitar, maybe some new tubes will fix it ?  Do you know what tubes are in it and how old they are ?  Flubby bass can also be exacerbated by the power amp, a higher dampening factor pulls the cone up tighter and helps resists the back wash from cone movement giving much tighter bottom end.
Title: Re: Muddy/Mushy bass - HELP!!
Post by: herbyguitar on October 13, 2017, 01:10:32 PM
I'm using a Mesa 2-fifty for power. Hardly any hours on it.
The tubes in the MP1 are about 25 years old but only about 10 years of playing. It sat in storage for about 15 years.
What tubes would get the tightest response?
Is it worth modding the MP1? Is there a mod that would tighten it up? I found this site:  http://www.marshalljmpmodshop.net/ada%20mp1%20modded%20tubeboards.htm
Title: Re: Muddy/Mushy bass - HELP!!
Post by: Systematic Chaos on October 13, 2017, 05:39:29 PM
The 2:50 is tight as hell since it's biased really cold.

If you wanna retain the overall Mp-1 tonal character just go for the EQ part of the Mod3.666 (Step10 in the 3.666 mod instructions):
http://adadepot.com/mods/ADA_MP-1_MOD3.666_Hi-Res.pdf (http://adadepot.com/mods/ADA_MP-1_MOD3.666_Hi-Res.pdf)
Title: Re: Muddy/Mushy bass - HELP!!
Post by: rnolan on October 13, 2017, 10:02:18 PM
Hey herbyguitar, 10 years playing on the tubes probably means time for new ones.  As for which tubes, it's very subjective.  Various members here have rolled quite a few options until they found the tubes that suit them and their playing style etc.  Have a good read through the posts in the tube section, lots of good info and opinions in that section. (start here: http://adadepot.com/index.php?board=40.0) (then here: http://adadepot.com/index.php?board=38.0)  Happy reading, may take you a while, tubes are a hot topic LoL (no pun intended).
Actually SC knows allot (and has posted much knowledge) re different MP1 tube choices.
So you found MJMPs website.  It's a good place to check out and MJMP is very good to deal with.  MJMP is our resident ADA tech guru  :bow:
Yes it's worth modding the MP1.  They are getting quite old so some people are just replacing parts (particularly electrolytic capacitors that have gone hard inside) to give the unit a new lease on life and keeping the tone stock.  Others prefer some of the mods for various reasons...more gain, particular tones etc.
Title: Re: Muddy/Mushy bass - HELP!!
Post by: MarshallJMP on October 14, 2017, 08:17:33 AM
I would try some new tubes first. It's easy to do and can give you instant results.
Title: Re: Muddy/Mushy bass - HELP!!
Post by: herbyguitar on October 14, 2017, 04:27:49 PM
I like this site. You guys are great.
Tubes first. See what happens.
Thanks for the advice. I'm not much of an electronics dabbler. I've wired guitars and done simple pedal mods but nothing like tearing into an amp or preamp. That said, the prospect does not scare me... much.

[edit] I found something very helpful in this thread http://adadepot.com/index.php?topic=1732.0 (http://adadepot.com/index.php?topic=1732.0)
He set his EQ up like this: Master 6.0 / Bass 9 / Mid -12 / Treble 0 / Presence -8. I tried it and found out something I had forgotten over the years. Mids and presence will kill articulation in an MP1. This jogged my memory from the 90's when I used the MP1 religiously. I recalled a couple of settings I used to use for specific things. For kick butt Marshall type rock chords and medium to slow solos I set my bass up, mids up, treble scooped, presence maxed. Great woody Marshall tone. For quicker solos and good articulation I set my bass up, mids scooped, trebel up, and presence scooped. Great for fast riffing. I forgot all this in the intervening years from 2002 to 2012 (my hiatus years). I just purchased a Boogie 2 fifty almost brand new off Ebay for 550. No marks and used for only a couple hours. I guess the previous owner didn't like the way the boogie amp colored the sound. Not a problem for me though  :)   MP1 Tubes still on my list. Replacing them tomorrow. Going to try JJ ecc83s first.

The description of the mods is not really that helpful. There are holes in the descriptions. I'm thinking that I will probably need a mod for the frequency response for lows and mids more than amything. Maybe a refurbish mod to replace old parts with new ones.... caps and transformer???
Title: Re: Muddy/Mushy bass - HELP!!
Post by: rnolan on October 15, 2017, 12:51:55 AM
Hey hg (Hmm maybe I should call you Mercury LoL), the JJs should work well and they are a reasonably "tight" tube.
I was going to suggest you check out DJCs threads, seems you found them yourself  :thumb-up: .  He didn't like the boogie power amp colour and now uses a Marshall power amp.
The noise mod and a MDRT is a good place to start.
Maybe start a new thread (Pimp my MP1 or whatever ) so we can all chime in as you go.  And maybe also do a post in Introduce Yourself (http://adadepot.com/index.php?board=34.0) and tell us what gear you have, playing style etc  :wave:
Title: Re: Muddy/Mushy bass - HELP!!
Post by: rabidgerry on October 16, 2017, 01:22:20 PM
herbyguitar

the way you ran the tube screamer wasn't they way I would have run it,

I tried putting a tube screamer in front. I pulled down the gains to about 3 and ran the screamer @ around 75%. I also pulled down the EQs to zero except the mids which I ran @ -4. Ran a parametric in the effects loop set at +3db @ 80hz medium band. -3db @ 3.35khz wide band. +3db @ 4.25khz wide band.... seemed to get me close to where I want to be but still not tight enough for my taste. It's been years since I stopped using the MP1 and I don't recall why but this flubby bass problem may be the reason I retired it...

I would have ran it at

Tube Screamer
overdrive: 0%  (or as low as you can get it)
tone: 50%
level


Then stick that in front of a hi-gain MP1 patch (obviously modify it with the EQ to suite the new characteristics the pedal introduces)

I find anything with any pedal in way of it's own gain to suck ASS.  That's why an EQ works good in front as MJMP has suggested in the boost thread on here.
So I make my MP1 do most of the work and literally add the "3rd dimension" using the boost
Title: Re: Muddy/Mushy bass - HELP!!
Post by: Systematic Chaos on December 09, 2018, 05:38:55 PM
Reviving this thread....
I just did the big noise mod to an MP-1 v2 and while at it also swapped all other caps (did the ones as per noise mod: 10uF 450, 2x 33uf 250v (all Panasonic) 5x 33uf 50v (ELNA RFO series).
All others were swapped as follows:
- C3, C9, C10 with Orange Drop 715P 0.0068μF
- C4, C11 with Mica 100pF/1kV
- C5 with Orange Drop 715P 0.015μF
- C14 with WIMA 2700pF
- C15 with Orange Drop 715P 0.01μF

While the unit is almost dead quiet the tightness in the bass is completely gone. Anyone (MJMP) know what the reason could be?
I can get it tight with an OD or DS as clean boost up front but the bass response is overbearing without.
Since these were the only parts I swapped (to the same values as the originals) in addition to the normal noise mod I'm thinking maybe tinkering with the values (of the caps/resistor on the tube board) to get a tighter bass response......?? I'm talking the bass response within the tube stages, not the eq section

@MJMP: Any chance you can shed some light on those 10caps to be replaced for the Standard Gain SS Mod you mentioned here:
Well the SS mod can be orderd as a standard gain and as an increased gain board.But i usually sell the standard ones because in 90% of the cases these have enough gain unless you have very low output PU's.The SS mod is almost identical to the original except for about 10 caps that have a different value,mostly for tone and noise changes.It makes the tone a bit tighter and brings the noise down compared to the original board but retains the original sound.