MB-1 Err 1 + Err 7

[rafammbass]

Hi Everyone,

I have owned a MB-1 up until 2018 when I sold it on eBay.

Now I have found a unit on eBay that looked real nice for $300 presenting with Err 1 and Err 7 - which should basically be the battery. No issues here, very skilled with soldering and fixing/modding stuff.

Here is the listing: MB-1

One thing I learned reading this forum is that the heaters run a little cold. Shame on me I have never measured the voltage on my old unit. I have emailed Philippe regarding one of his transformers, but still waiting to hear back from him.

Any other mods that can benefit the MB-1? Asides from replacing old electrolytics, of course.

Thanks!

[rnolan]

Hey rafammbass, welcome to the depot

Wow good score .  From my experience (I have 2 MB-1s) they are very solid units.  The MDRT is a really good improvement, I sent the 2 I bought (US versions) via MJMP in Belgium for the MDRT and to make them 240v for Australia.  The other thing worth doing is get the last EPROM v2.05 EPROMs when you order the MDRT.  The last EPROM includes CC control which I posted about ages ago, it's a little complicated to get your head around but very useful.  I use the master vol control with my MXC expression pedal.

I also put Mullard Long Plate 12AX7s in one of them which add some 3D depth to the sound, albeit the tubes aren't used in every patch.

I just read you previous post (2014) selling your previous one, so you know about the v2.05 already.

I've attached a couple of pdfs you may find useful

[rafammbass]

Thank you for the resources. I am actually perplexed this is coming with all box candy and a carrying bag. Yes, that unit I listed here in 2014 ended up moving to Canada with me and sold to someone in the States in 2018.

I will pick it up next week, crack it open and see what needs to be done. I am hoping it already has the v2.05 FW.

As for mods, still waiting on the belgium gentleman (MDMT?) to get to my email, although I can probably source a suitable transformer myself.

I don't remember not liking the sound, might be worthwhile get some better quality opamps in the signal path?

Cheers friend from down under.

[rnolan]

Hey rafammbass, new opp amps will probably help although both of mine, which I think are fairly stock just with MDRT and battery mod   sound great (I don't remember what else MJMP did to them apart from Australian power plugs which I sent him, he probably did the caps).  I have one in my studio rig and one in a live rack. Best sounding bass preamp I've ever come across.

[rafammbass]

I concur, just need to make sure I am on FW 2.05 - cannot find the eeprom anywhere so I can program it myself. I have not picked up the unit yet... Might have lucked out and gotten a upgraded unit. We'll see.

[rnolan]

MJMP has the EPROMs but he hasn't been around for a bit, maybe on holidays    Hopefully you do luck out and it's been done and the unit is a good one.

[MarshallJMP]

Sorry had some very busy weeks, but I'm back again.

[Harley Hexxe]

It's good to see you here again. 

[Peter H. Boer]

I don't remember not liking the sound, might be worthwhile get some better quality opamps in the signal path?

Better opamps will make a difference, both my MB-1s were upgraded.