ADA Depot - A Forum To Support Users of ADA Amplification Gear
ADA Preamps => Original MP-1 => Topic started by: PrimalScream91 on June 23, 2016, 01:43:26 PM
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Hello all, I am new to the forum and need help diagnosing a problem.
I'm running my MP-1 into the power section of a Blackstar HT40 but when I plug the MP-1 into the return of the Blackstar I get nothing. Only after dimeing the output on the MP-1 and turning up the Master on my Blackstar will I get any noise. Even then all I'm getting is the occasional LOUD note coming out of the speaker.
I believe this could be a problem with the jacks on the back of the A/DA but I'm not 100% sure.
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Yeah, those jacks do have a tendency to get brittle and fall apart. I've seen a lot of them look ok on the outside and completely broken up on the inside.....
Have you opened it up and looked in there yet?
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I have not opened it up yet, but that will definitely be my next step. I'll open it up and see if I can suss out the issue. I'll probably take pictures as well, so if I have any questions I'll post them.
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I found an old pic I had taken of one of those MP-1s that had some real buggered jacks. Hope yours aren't as bad as these were!
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This is what it looks like under the hood, I cannot see anything that looks particularly knackered, just dirty.
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I'm also unsure of the year it was built. I did find this inside of it, I wonder if that's a date?
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This looks like it's a late 89 early 90's unit, I saw a date code of 89 40 which means 1989 week 40.
You can also try to use the effect send as an output, so you could also try that one.And you can also try to plug in a headphone in the headphone out to see if the MP-1 works.
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Hey welcome to the depot :wave: ,
Also maybe try into the Blackstar input (test it works with just guitar first) and keep the MP1 vol down. If Blackstar input is working, then MP1 main out(s), FX loop send and headphone out should all work into it (albeit not optimal but it will test them).
Wow it is quite dirty inside, needs a good blow with some compressed air, they looked like original tubes also ?
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Kim, was that my MP1 that you modded? I remember you had to replace most of my jacks. :bow:
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Hey all!
This morning I cleaned out the jacks on the MP-1 as well as the Blackstar. The A/DA was quite dirty inside, so I figured i might as well test it to see if that was the issue. Sure enough the signal came in strong! Must have been an issue with all the buildup inside of that jack. Thankfully it wasn't anything too serious.
Thanks for all the help guys! It's nice to know there is a community dedicated to these old units.
As far as the tubes being original, I'm not sure, if there is any way to tell I'd be more than happy to take another look at them.
Thanks again!
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So all okay now?
Looks like the tubes are the original National tubes.
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Yep, all is good now!
I'll pop it back open and check the tubes, because now I'm curious! :lol:
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Take a look at the pic you posted ;D
Anyway these Nationals are just rebranded Chinese tubes as far as I can see.
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Yep, Chinese Nationals.
NATIONAL
12AX7/ECC83
MADE IN CHINA
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Never seen these before, the older MP-1's also had National tubes but these were not Chinese tubes.
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Good to hear it was an easy fix! Another testament to the process of "check all the easy things first before assuming the worst". :)
Kim, was that my MP1 that you modded? I remember you had to replace most of my jacks. :bow:
I honestly don't remember if this particular one in the pic I posted was yours or not...I actually repaired maybe 5-6 MP-1s back then that looked as bad as that. (I can't believe I happened to still have some of these pics anyway since I had lost a LOT of valuable data and irreplaceable pics in the several pc crashes I experienced back then. Yeah, my fault for not backing up all my shit every hour on a miserable p.o.s. Windblows OS, right?)
By the way, here's a pic of the repair if anyone's interested.
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Yep! I just know that these units are getting old and can start to develop problems, I'm glad that it was as simple as it was!
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They could be replacement tubes installed more recently.
I would recommend a fresh set of tubes for the MP-1. Avoid Groove Tubes since their quality has dropped a lot in recent years.
If you want a good full range sound in the MP-1, I would suggest some good quality. long plate tubes from Doug's Tubes in NY. You'll find that many of the members here like JJ's, but most of them sound a bit too brittle to my ears with one exception: ECC803. They sound smoother to my ears.
Currently, I'm using Penta 12AX7's in mine and I like them. Powerful, a lot of bass and low mids with good clarity. Overall, a fair HiFi tube for the MP-1.
Also, Mullard Reissues will make the MP-1 grow some serious balls if you can get some of those in good quality. There are Russian made reissues on the market now, but I tried a pair in my MP-1 Classic, and they wore out after just 3 months. Maybe it was the pair I happened to get, I don't know. The Penta's seem to deliver a very similar tone for the MP-1.
In the end, it's what your ears like to hear that really matters, so there are no wrong choices for preamp tubes!
Harley 8)
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They could be replacement tubes installed more recently.
I would recommend a fresh set of tubes for the MP-1. Avoid Groove Tubes since their quality has dropped a lot in recent years.
If you want a good full range sound in the MP-1, I would suggest some good quality. long plate tubes from Doug's Tubes in NY. You'll find that many of the members here like JJ's, but most of them sound a bit too brittle to my ears with one exception: ECC803. They sound smoother to my ears.
Currently, I'm using Penta 12AX7's in mine and I like them. Powerful, a lot of bass and low mids with good clarity. Overall, a fair HiFi tube for the MP-1.
Also, Mullard Reissues will make the MP-1 grow some serious balls if you can get some of those in good quality. There are Russian made reissues on the market now, but I tried a pair in my MP-1 Classic, and they wore out after just 3 months. Maybe it was the pair I happened to get, I don't know. The Penta's seem to deliver a very similar tone for the MP-1.
In the end, it's what your ears like to hear that really matters, so there are no wrong choices for preamp tubes!
Harley 8)
Cheers man, I'll definitely start looking into getting a new set of tubes. I'm relatively familiar with power amp tubes, but not so much preamp tubes, so this helps a lot!
Also, what's your opinion on Sovtek tubes? I know a lot of people like them.
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Hey PS91, One thing about the various 12AX7s available, while all being electrically compatible with your MP1, they all sound different. Like Harley, I like the long plates, they seem to have more depth and "3D" articulation which suits my playing. Short plates work well for other styles, particularly very high gain (from comments here). When you have some time to spare, read through the tube posts, it's quite long but lots of good ideas, opinions, some technical stuff, pretty much all the good (worth buying) tubes get a mention. Also you can mix and match. MikeB uses a Mullard re-issue short plate in V1 position and a Boogie SPAX7 (re badged JJ) in V2 and this setup works for him. The Sovteks are a bit cheaper than some others and there's a few to pick from (http://www.dougstubes.com/preamp-tubes/12ax7-ecc83-7025.html). They are made in the same factory as the Mullard re-issues and a few other nice brands like Tung-Sol.
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Hey PS91, One thing about the various 12AX7s available, while all being electrically compatible with your MP1, they all sound different. Like Harley, I like the long plates, they seem to have more depth and "3D" articulation which suits my playing. Short plates work well for other styles, particularly very high gain (from comments here). When you have some time to spare, read through the tube posts, it's quite long but lots of good ideas, opinions, some technical stuff, pretty much all the good (worth buying) tubes get a mention. Also you can mix and match. MikeB uses a Mullard re-issue short plate in V1 position and a Boogie SPAX7 (re badged JJ) in V2 and this setup works for him. The Sovteks are a bit cheaper than some others and there's a few to pick from (http://www.dougstubes.com/preamp-tubes/12ax7-ecc83-7025.html). They are made in the same factory as the Mullard re-issues and a few other nice brands like Tung-Sol.
I glanced through some of those posts yesterday but I was in a bit of a rush, I plan on going back and reading into them this afternoon. So far, long plates sound like my preference.
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I've had really good results with the Mullard long plates in my (now 4 :facepalm: ) MP2s. Seems strange that Harley didn't get much wear out of his in the Classic :dunno: I've not had a longevity problem with them. Systematic Chaos put me onto them. He tried them in his MP1 and liked them (although I think he had some new old stock (NOS) Mullards ??, these are expensive)
There's also some good links etc in that thread to help you get your head around the variables.
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Since Harley posted I've been looking at both the Mullard's and the Penta's. I assume it couldn't hurt to try some Mullard's, as Harley said, maybe he just got an off set.
Looking at dougstubes.com, it looks like they're not selling the Penta's anymore, because that product page states: "Warm, fat tone. We are now shipping 12AX7AC5 HG's in place of Penta's." After searching it looks like they might be shipping the RUBY 12AX7AC5 HG's in their place, so I assume they are similar tubes.
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Like many brands, Ruby buy tubes , test them etc and re badge them (same with Groove Tubes, EH, Boogie etc). Last look there were really only 3 factories, Slovakia, China and Russia from whence they all come... I can certainly vouch for the Mullards in a MP2
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Right on! Thanks for the advice & wisdom! :cheers:
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Well I'm more a JJ user but I get the Ruby 12ax7ACZ HG which are JJ's tested by Ruby. Now I don't recommend sovtek because they sound dull in a MP-1.
As for Penta ,they do the same thing as Ruby, they buy Chinese tubes and test them. So the Penta 12ax7a and the Ruby 12ax7AC5 are actually the same Chinese tube. It's quite easy to recognise Chinese tube, they have an extra spacer that only Chinese tubes have.(see pic)
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Well I'm more a JJ user but I get the Ruby 12ax7ACZ HG which are JJ's tested by Ruby. Now I don't recommend sovtek because they sound dull in a MP-1.
As for Penta ,they do the same thing as Ruby, they buy Chinese tubes and test them. So the Penta 12ax7a and the Ruby 12ax7AC5 are actually the same Chinese tube. It's quite easy to recognise Chinese tube, they have an extra spacer that only Chinese tubes have.(see pic)
it is interesting how companies will buy tubes to test and rebrand them. Right now I'm looking between the Mullard Reissues and the 12ax7AC5's.
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If you can afford it, buy a pair of each then try each combination. You may find you like 2 of the same, or say a mullard in V1 and the Ruby (JJ) in V2 (or vis versa).
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Hey PrimalScream91,
I'm not really a big fan of the Sovtek brand personally. I haven't actually tried those in any of my ADA preamps, but I did try a few in one of my vintage Fender twins, and they only lasted about 3 minutes. That's because it only took me that long to find out that they didn't give my amplifier the classic clean tone it's known for. They break up WAYYYY early and distort too easily, so I don't imagine they would be suitable for a preamp like the ADA's.
The Ruby's as MJMP mentioned, are Chinese tubes, but one of the few Chinese tubes I would look into. I would more than likely look at the Higher priced Ruby Tubes, and those with ratings suitable for HiFi equipment, The 12AX7ACZ or the 12AX7AC5 you mentioned, might be along those lines. I have a trio of the 12AX7ACZ's in my 3TM, and they aren't bad at all.
Yes, I probably got a bum set of Mullard RI's that went South after 3 months in my Classic, but I got those through Musician's Friend, so who knows how long they had them sitting around? The Mullards in my MP-2's I got from Doug's, and they are still going strong. I'm still tube-rolling with the Classic to see if I can get some more pleasing results with it.
To my ears, short plate tubes seem to have a lot of high-end harshness, so I look for more low mids and bass, and that's where the long plate tubes seem to generally fill the bill. Still, there are a few short plates out there that have some enhanced low frequencies, but not many.
It's a lot tougher these days to shop for tubes since you can't really go into a music store and roll a few tubes through your amps like we used to do in the old days. That's one of the priceless benefits of this Forum. Players here are always trying different things, and you can get a pretty good picture in your mind of what you are looking at because chances are, someone here is already using it.
Harley 8)
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Hey Harley,those 12ax7ACZ are actually JJ's and the AC5's are Chinese.
Best is not to buy tubes of the shelf at a music store, usually these are bad quality. These are mostly the rejected leftovers that companies like Penta, GT and Ruby resell. Also if you're in the US I can recommend Doug Tube, great guy never had any issues with the tubes I bought from him. And okay you pay more but you also get the quality! Too bad the dollar has gone up and with the import taxes it's just too expensive to buy tubes from him.
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I couldn't agree with you more MJMP, the last batch of tubes I bought were all through Doug's. So far, so good.
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Thanks for the input guys! :thumb-up:
So when I go to order my new set, would it be worth it to get a Matched Pair? Balanced Triodes? High Gain?
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I always ordered the high gain balanced triodes types.
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Thanks for the input guys! :thumb-up:
So when I go to order my new set, would it be worth it to get a Matched Pair? Balanced Triodes? High Gain?
Matched sets of tubes really matter only in Power Tubes. It's not really that kind of an issue with preamp tubes. In fact, there are many people here who use different pairs of tubes in their equipment to control the gain structures more to their liking.
Typically, in preamp tubes, it's important to have the mu rating on Triode 1 equal to or less than the mu rating on Triode 2, (Mutual Inductance). The preamp tube will just sound bad if Triode 1 is higher.
This is why many of the members here use different preamp tubes in their gear, they might use a medium gain tube in V1, and a higher gain tube in V2 for a smoother cascading gain structure. On the other hand, They might reverse that for a more abrasive gain structure. It's all subjective to taste. In stock preamps, I like to use strong gain rated tubes because it still produces good clean tones with slight differences in the EQ, (depending on the tubes I use), and still gives me good overdrive/distortion tones. The exception to that is the MP-2 since it has much higher distortion ratings as a stock unit.
Modded MP-1's are an open canvas as far as tube rolling goes. I only have a 3TM which I'm using with my stock MP-1 just to give me the extra gain when I go into a solo. It's a combination that works well for what I need.
Harley 8)
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Right on! :thumb-up:
I'm thinking about pulling the trigger on some Mullards, I'll be sure and post what I think!
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I had the same issue with my stock MP1 (now roided up to an MDRT/Noise Mod hellhound)
I used output B when A seemed to fail on me. I intend to replace Output A, but recently it has been working fine. So probably just needed a clean.
Boy you MP1 is dirty inside lol
My stock MP1 has the original tubes in there still. I really like them. When they die I will put in the TADs that Systematic Choas recommended, these are the closest thing to the stock tubes in the MP1 you see.
this is the model: TAD 12AX7A-C RT001
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Hey RG, Those stock tubes went forever, great tubes for the MP1.
Hey PS91, Check out DTs FAQs, a good read :thumb-up:
From Dougs FAQs:
http://www.dougstubes.com/faq#z1
Balanced: When the plate current draw of each triode is the same, we refer to that as having balanced triodes.
High Gain: Tubes that measured to have higher gain.
Matched: Each triode of the preamp tube has matching gain.
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Hey RG, Those stock tubes went forever, great tubes for the MP1.
Hey PS91, Check out DTs FAQs, a good read :thumb-up:
From Dougs FAQs:
http://www.dougstubes.com/faq#z1
Balanced: When the plate current draw of each triode is the same, we refer to that as having balanced triodes.
High Gain: Tubes that measured to have higher gain.
Matched: Each triode of the preamp tube has matching gain.
Richard,
That is in reference to matched triodes in the preamp tubes. Primal's question was about a matched PAIR of tubes in the preamp which doesn't apply here.
Harley 8)
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Boy you MP1 is dirty inside lol
"Was" dirty inside! I cleaned that bastard out! :lol:
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Boy you MP1 is dirty inside lol
"Was" dirty inside! I cleaned that bastard out! :lol:
Good work :thumb-up:
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Hey Harley, yeah I understood that, and you answered it in your 1st post ? IIRC, as in this scenario it's not important as is an input stage not a push/pull output stage. I put the other stuff there to help understand the other variables. e.g. the difference between matched pair and matched triodes.
Go PS91, it was pretty dirty :facepalm: , it will like for a good clean :thumb-up:
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Boy you MP1 is dirty inside lol
"Was" dirty inside! I cleaned that bastard out! :lol:
Good man! Glad to hear it :)
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Got the new tubes in today, matched set, high gain, balanced triodes, the Mullards won out. It might be the snake oil talking, but it definitely seems like my amp has been opened up.
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I'd say that is a pretty good indication that it was time for a new pair. Enjoy!
Harley 8)
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I'd say that is a pretty good indication that it was time for a new pair. Enjoy!
+ 1 :thumb-up: . It's also a feature of those longplates, they are a very "open" tube/soundscape (which is not what everyone wants). They'll also improve a bit as they burn in. I've got a few pairs arriving tomorrow (hopefully) for my MB1s.