Help: Bartolini on Yamaha TRB6

[eunchang]

Hey. This is my first posting so please help me out.

I have a Yamaha TRB6(old model, more than at least 6 years old). Unfortunately, neck pickup gone dead a while ago. I ordered a pair of Bartolini G6 and installed them myself(I have no idea about electronics at all..I just cut the wires from the old pickups and connected).

I got some sound, but not the right sound. Output level was too weak so I turned the trim pot all the way up to compensate. It helped a bitr but still the total output level was weaker than the one from the stock Yamaha pickups. Also, there was too much hiss; it was not tolerable from the monitors. I even got a very dissapointing comment from a recording engineer worked with(he thought it was a really weird bass sound). :scowl:

Today, I brought my bass to a local repairshop and the guy was willing to help me(even though I was bothering his late lunch), however, he doesn't look like he really understood the problem. He pluged my bass into a big cabinet and played a couple of notes really loud and said this bass is one of the most quiet bass...duuuhhhh. He even showed me one of the shop's basses which had really big noise problem and tried to assure that my bass was alright. He said most of the preamps have the relatively same amount of hiss and mine was in a good shape.

But,

I came back to my place and tested again through my Mackie mixer/Samson monitor and the hiss was so obvious. I A/B tested with my other bass(Nordstrand NJ4 Deluxe) and that bass was dead quite while there was a big hiss coming out of my TRB(feels like an ocean). There was a huge difference. Actually it doesn't even need A/B test. Now I cannot trust the only repairshop in my town(as far as I know), I don't expect much from the Guitar Center.

That why I need your help. Does anybody know what causes the problem??

Does Bartolini G6 go along with Yamaha stock preamp??

Or I just wired them wrong??

Should I simply replace the whole electronics?? (in this case, I will get a prewired one rather than bring it to that repair guy)

Any thoughts will be welcomed.

 

[David Wilson]

I don't know anything about stock Yamaha preamps. But I'll help where I can with some general questions.

Were your previous pickups active? i.e. were they wired into the battery also? It could be that the stock preamp was expecting an active signal? Also, there might be some impedance issues with putting the passive pickups through volume / blend pots meant for active pickups.

In general, Barts are well known as generally quieter pickups. If you're going to replace with a Bart pre-wired preamp, I'd heartily recommend Brian at bestbassgear.com. He has just about every bart preamp configuration available. Even buying a pre wired config, you'll need to a little bit of work yourself: soldering the pickup hot/ground wires and soldering the jack if it's a long shaft jack rather than the standard shallow jack used on a Jazz etc.

Hope this helps! Hopefully someone with direct Yamaha knowledge can help you out more.

 

[eunchang]

Thank you so much.

I am not sure the stock pickup was active or passive. The only thing I remember is the pickup itself was not connected to battery.

If it is the impedence mismatch you mentioned(to be honest I don't really know what it means), what can I do?? Is there anything I can do with these pickups and preamp?? Or getting a new preamp is the only way to solve the problem??

 

[David Wilson]

if the pickup wasn't connected to the battery, it's not active. And therefore you almost certainly don't have an impedance mismatch. It was a long shot anywya.

Again, I don't know many / any specifics about Yamaha electronics. But it sounds like the preamp expects a hotter output, hence the hiss issues (amplifying a lower volume signal, and so the signal/noise ratio suffers).

I think you might have to replace the preamp, or replace the pickups with higher output ones.

 

[eunchang]

Thanks so much David,

one last question before I spend another $170 or so.

I was checking out some preamps at Bestbassgear.com(the place I purchased Bart pickups) and I found there is "ground wire" from the bridge I should connect with the pickups.

I didn't see any ground wire thing from the cavity room, I didn't connect any wires other than going directly to the on board electronics.

Do you think that can cause hiss also?? Sounds pretty stupid but I just don't know anything about electronics.

Actually I am considering buying a preamp but, either way I think I need to figure out the ground wire.

 

[David Wilson]

You wouldn't necessarily have touched the bridge ground wire while changing pickups. The bridge ground wire needs to go to ground - it may be wired directly to the ground on your jack.

But check in your control cavity for wires coming in from outside the cavity. If your battery box is outside the cavity, you'll see both +ve and -ve battery wires (red and black usually). Is there another single wire coming from outside?

Either way, it wouldn't cause hiss but could cause buzzing.

 

[eunchang]

Hey David,

I've decided to get a Demeter one(I didn't place an order yet though).

I am looking forward to have it on my bass 'cause it has been so long having trouble with that bass!! I hope a new Demeter will be the answer.

Thanks for your help.

Ah, one last question.

I took out the old preamp already just to see, and I found two ground wires. One is connected from the bridge to the output jack, so easy. But the other one is connected somewhere from the board to the cavity. Do I need to connect that second wire with the Demeter preamp?? Then where and how??

 

[David Wilson]

I took out the old preamp already just to see, and I found two ground wires. One is connected from the bridge to the output jack, so easy. But the other one is connected somewhere from the board to the cavity. Do I need to connect that second wire with the Demeter preamp?? Then where and how??

I don't quite understand what you mean by 'from the board to the cavity'. Could you describe where it starts and ends exactly - if it goes to a lug on the jack, which one?

If it's going to it's own lug on the jack, i.e. no other wires are connected there, then it may well be the battery -ve.

A photo would help immensely here.

 

[eunchang]

Hey David thanks for your concern.

Here are two pics.

You can see a wire is coming from the board right?? just hanging..that is soldered on the board not on the pot. But it is attached right next to the blend pot.

That wire was grounded(I guess) to the cavity by a small bolt which I left on. It is tiny but you may see it if you click on the picture. It is upper left side of the cavity.

Wires coming from the left side are from the pickups and the others are attached to jack and also a ground wire from the bridge.

 

[David Wilson]

hmmmm.

I'm wondering if that's a star ground point - a method giving a common ground point for pickups etc - or a ground for the cavity itself.

I'm thinking it's an unused star ground, but if anyone else wants to chime in please feel free to do so. In that case, you shouldn't have to bother with it with your new preamp if it's all grounded ok.

 

[eunchang]

I got the Demeter pre yesterday and didn't install yet. I am just being careful 'cause I don't know a thing!!

Unfortunately, I think I cannot use the output jack came wired with the pre. It won't fit in the hole.

Do you think that I can hookup the ground wire from the pickup to the "star ground" you mentioned?? Or grounding to the jack will be the best way??

 

[David Wilson]

You're going to need to replace the jack which will involve unsoldering the old one and soldering to the new one.

As for grounding, there are different methods. At some point, the ground has to go to the jack. I don't know how Demeter pre's are wired, but standard practice is usually to ground the pickups to the back of a volume / eq pot and make sure that pot itself has a connection to ground.

If you haven't done anything like this before, I'd recommend getting a tech to do it.

 

[eunchang]

You're going to need to replace the jack which will involve unsoldering the old one and soldering to the new one.

As for grounding, there are different methods. At some point, the ground has to go to the jack. I don't know how Demeter pre's are wired, but standard practice is usually to ground the pickups to the back of a volume / eq pot and make sure that pot itself has a connection to ground.

If you haven't done anything like this before, I'd recommend getting a tech to do it.

thanks for your concern david, BUT I DID IT MYSELF!!

yes i haven't done modification so i brought my bass and new pre to one and only repairman in my town(as far as I know) this morning. however, he was keep asking manufacturer's schematic. It looked so obvious even in my eyes...every wires are hooked up with pots, the only two wires are out there waiting to be connected with the pickup wires. And he was complaining about not knowing how to figure out which pot will be treble and which one will be bass..duhhh.

he said be back with the schematic but I just gave a try myself.

I unsoldered the new jack and soldered wires on the old one because new jack didn't fit in. I also kept the old battery cavity so I just cut the wires from the new one and soldered them.

I tried grounding both ways-on the output jack sleeve and on the bolt I mentioned. Actually, grounding on the bolt worked fine and in that way I might be able to save a little bit of wires because the bolt is located pretty close to the pickups. However it wasn't as stable as soldering on jack. So I used the standard method.

Because I was worried too much about messing up I left all the wires pretty long. That made the cavity filled with wires. I heard this may cause some noise but so far it is much, much, quieter than before. I still think my NJ4 is a bit quieter, but I am happy.

AND THE SOUND!!! Whooooaa!! Thanks everybody who recommended the Demeter. It sounds really clean and WIDE OPEN.

This was my first try of modification on my electric bass(I have been working as a double bass player mostly..I play more on the electric these days). Thanks to the repairman who wasn't really cooperative, I've learned a lot. When I got the first sound, i mean the first sound after I've put much effort on the instrument, it felt great. Every bit of struggle paid off.

Thanks everybody.

 

[David Wilson]

that's great! glad you're liking it.

 

[eunchang]

that's great! glad you're liking it.

Am I liking it?? I think you didn't understand what I meant

I AM LOVING IT!!!!!! BARTOLINI+DEMETER!!!!

 

[Lackey]

Ahem, lemme just bring this one back from last year...

eunchang, I've got a 1st generation TRB6 myself, and I'm looking to get a bit more low end out of it. How do you feel about the G6 Barts? Do they have a nice burpy midrange as well? Do they drop directly into the TRB6 pickup cavitys or do they need a bit of convincing?

If I do it, I'll throw a Bartolini 5.4 preamp in it as well.

thanks!

 

[Matt Power]

Have Carey Nordstrand whip you up a set of his 6 string jazz pickups, and have him make some ebony covers for them; then wire it up to an Aggie OBP-3, and hang on! The first thing you'll do after hearing that combo is go change your boxers, 'cause you'll drop your mud!!

Call him...IMO, the best pickups out there.

 

[john keates]

I have an old trb5 and I got a load of hiss from it. I replaced the pups with passive Villex. Much better now.

Those old pre-amps were horrible - LOTS of hiss.