Fretless wonder Part 2

Bridgehouse

Following on from my head scratcher....

..I have discovered that the Ghost system is the issue. The shielding didn't work. The board itself is foo-barred. It got to the stage where it actually stopped amplifying anything other than the interference and thus is Kaput. Seems also that the "summing board" that takes the 4 individual piezo saddle pickups and turns them into 1 "hot" and "ground" connection was also knacked. To be fair, it's 10 years old so it's had a good run. @ICBM - turns out the head scratcher was knackered hardware!!!

So...

I'm going to redo the innards completely. I will need to use a new set of Ghost ABM Piezo saddles and a new summing board to get my piezo output back to Hot and Ground. They are ordered and hopefully on the way soon.

My experience of actives has been mixed - but universally I've been impressed with the East Preamps - the man makes some lovely kit and I have a P-Retro in my ACG as an upgrade. So - I really would like to go East. This also means I'm using single manufacturer and single system. This should be much better and as @ICBM will attest - it cuts out a lot of the crap by using a single system.

I need to call him to discuss, but he does seem to be a difficult chap to get hold of. 

I think the way to do what I want to do is to get an East MPM 02 Piezo Mag mixer - which I can either use to mix the Mag and Piezo directly, or use it to preamp just the Piezo signal and output to something else.

I also want to have an active boost circuit for the Mag - preferably his Uni-Pre 3 knob system. Interestingly this allows two pickup inputs which can be mixed on the vol board by two 12db trim pots. So I could either blend using the mixer on the MPM-02, or go from the MPM-02 with just piezo and blend on the Uni-Pre 3 knob. 

Controls would thus be:

Vol/Blend Pot - UP3
Piezo Tone (high freq roll-off) MPM-02
Mid Freq stacked knob with Mid Freq Sweep - UP3
Treble/Bass stacked knob with Pull for Bright - UP3

Switch 1 - Active/Passive
Switch 2 - ??

So - I'm a little unsure as to how to plan the details tbh - I have a spare switch hole at the moment - now I could get a different 4CW Jazz pickup with split or stacked coils and have a series/parallel switch in there, or I could put it as a power on/off switch and forget all the crap with the barrel jack and plug switching. Hmm. 

Similarly, do I keep the piezo on the MPM-02 and then put the mags through the UP-3 and mix them on the MPM-02? That means the blend on the UP-3 is not needed, and I don't get the EQ on the piezo either (the tone on the MPM-02 for the piezo is purely for harsh treble roll off) 

My preference would be:

Piezo -> MPM02 -> UP-3 input 1 (with tone roll off as knob 2)
Mags -> UP-3 input 2 with Vol/Balance Mid/Sweep Treble/Bass and active/passive switch

Out to the jack with switch 2 as an on/off kill switch.

I know @Andyjr1515 has done an MPM-02 before so would welcome your thoughts, Andy.. also anyone else that might have a clue WTH I'm trying to do....

Funkfingers

In your position, I would start from the other end. 

Since you like East products, begin by seeing what pre-amp systems he makes that might be applicable to your instrument. If East recommends a particular make/model of piezo saddle element to match with his buffered PCBs, follow his advice. 

Bridgehouse

Funkfingers said:

In your position, I would start from the other end. 

Since you like East products, begin by seeing what pre-amp systems he makes that might be applicable to your instrument. If East recommends a particular make/model of piezo saddle element to match with his buffered PCBs, follow his advice. 

I’m a bit restricted on the piezo elements due to the design of the bridge - it’s ABM or none. The ghost ones are no different to anyone else’s and they make them compatible with anyone’s Preamp by ensuring they are a balanced straight output.. theoretically they are just uncoloured piezo elements. 

Plus, I can’t find anyone else that does ABM style piezo saddles

Bridgehouse

Oh, and the UP3 is exactly what I wanting terms of Preamp - his piezo module seems to be an add on

Funkfingers

Open your wallet and repeat after the salesman, "help yourself."

Bridgehouse

Funkfingers said:

Open your wallet and repeat after the salesman, "help yourself."

I’ve done that too many times to fall for....



.....ah shit

Andyjr1515

I'll read this fully when I have a moment but yes - the 'summing boards' on Ghost systems are scandalously rubbish and utterly not fit for purpose.

Don't get me wrong.  I think Graphtech is a good Company and make some good products.  But to let their very expensive and powerful systems to be entirely dependant on such a cheap and unreliable bit of tat is utterly shoddy.  Graphtech - you are better than this! Bl***y well sort it!!!!

The last system I installed, I just snipped all the piezo wires and soldered them.  Only way of making it work.  Outragreous.

Based on your experience as well as my multiple ones, I will contact them AGAIN.

Bridgehouse

Andyjr1515 said:

I'll read this fully when I have a moment but yes - the 'summing boards' on Ghost systems are scandalously rubbish and utterly not fit for purpose.

Don't get me wrong.  I think Graphtech is a good Company and make some good products.  But to let their very expensive and powerful systems to be entirely dependant on such a cheap and unreliable bit of tat is utterly shoddy.  Graphtech - you are better than this! Bl***y well sort it!!!!

The last system I installed, I just snipped all the piezo wires and soldered them.  Only way of making it work.  Outragreous.

Based on your experience as well as my multiple ones, I will contact them AGAIN.

Thanks @Andyjr1515 - yes the summing board is a bit tat - either way, I’ll use the ghost piezos as they fit and seem really good - but you are right it may be better to solder them together - how did you do yours? 

I guess the big question is how I configure an easy setup to get it to do what I want?

Andyjr1515

Bridgehouse said:

Andyjr1515 said:

I'll read this fully when I have a moment but yes - the 'summing boards' on Ghost systems are scandalously rubbish and utterly not fit for purpose.

Don't get me wrong.  I think Graphtech is a good Company and make some good products.  But to let their very expensive and powerful systems to be entirely dependant on such a cheap and unreliable bit of tat is utterly shoddy.  Graphtech - you are better than this! Bl***y well sort it!!!!

The last system I installed, I just snipped all the piezo wires and soldered them.  Only way of making it work.  Outragreous.

Based on your experience as well as my multiple ones, I will contact them AGAIN.

Thanks @Andyjr1515 - yes the summing board is a bit tat - either way, I’ll use the ghost piezos as they fit and seem really good - but you are right it may be better to solder them together - how did you do yours? 

I guess the big question is how I configure an easy setup to get it to do what I want?

The hot wires and the returns are easily identified (I might be misremembering, but the +ve have a blue line?)  So just seperate a cm or so of each wire, then solder the 4 hots together and the 4 returns together.  The hots go into the piezo +ve on the board and the returns go to the piezo          -ve/ground on the board.

Funkfingers

Andyjr1515 said:
solder the 4 hots together and the 4 returns together.  The hots go into the piezo +ve on the board and the returns go to the piezo -ve/ground on the board.

This approach is what Fishman took on their HT100P Powerbridge for Telecaster. The output from the piezo elements is summed to one positive/hot and one negative/screen. Simple but effective.

Bridgehouse

Funkfingers said:

Andyjr1515 said:
solder the 4 hots together and the 4 returns together.  The hots go into the piezo +ve on the board and the returns go to the piezo -ve/ground on the board.

This approach is what Fishman took on their HT100P Powerbridge for Telecaster. The output from the piezo elements is summed to one positive/hot and one negative/screen. Simple but effective.

Sounds like that’s the strategy then...

Bridgehouse

Quick update - got an email back from John East - he's an incredible guy. Looks like there's options so just need to refine the final solution and knob layout (ooer)

Pending a solution from him, it means my final issue is these damned piezo saddles and wiring them together! They are really small little buggers and I'm a bit concerned my soldering isn't up to it - due to the routing they have to be done post install though. Gah.

Andyjr1515

Funkfingers said:

Andyjr1515 said:
solder the 4 hots together and the 4 returns together.  The hots go into the piezo +ve on the board and the returns go to the piezo -ve/ground on the board.

This approach is what Fishman took on their HT100P Powerbridge for Telecaster. The output from the piezo elements is summed to one positive/hot and one negative/screen. Simple but effective.

Yes - and that is all the Ghost 'summing board' does.  It is bewildering that they should use a connector - for absolutely standard 2pin connectors -  that simply does not work.  The average pc contains dozens that do work.  They've replaced the block for me on request without question  more than once which tells me they know they are using a duff  component.  We are talking about something that costs them a few cents, if that, on a system that they sell for hundreds of dollars.  

I don't generally get het up about such things but it is commercially poor at best and negligent at worst not to fix it.

Bridgehouse

@Andyjr1515 - have you got any pics/advice on your home brew solder connections? I’m thinking solder each to a single wire and run that to the Preamp?

Funkfingers

Bridgehouse said:

just need to refine the final solution

Heavy. Fascist.

Andyjr1515

Bridgehouse said:

@Andyjr1515 - have you got any pics/advice on your home brew solder connections? I’m thinking solder each to a single wire and run that to the Preamp?

I'll have a peep.  What you suggest, though, is a perfectly valid solution.  

Andyjr1515

Andyjr1515 said:

Bridgehouse said:

@Andyjr1515 - have you got any pics/advice on your home brew solder connections? I’m thinking solder each to a single wire and run that to the Preamp?

I'll have a peep.  What you suggest, though, is a perfectly valid solution.  

No - no picture.

As the piezo wires are so fine and there are only four that would be wrapped together - and bearing in mind that the pre-amp is a screw-block connector? - then your idea is probably a good one

Bridgehouse

@Andyjr1515 - went with the solder to two wires Took a while and was like knitting a jacket for a fly, but...

Andyjr1515

Bridgehouse said:

@Andyjr1515 - went with the solder to two wires Took a while and was like knitting a jacket for a fly, but...

Excellent

Bridgehouse

Now fitted mag back in and tidied cables... just an electronics set to source!

normula1

Looks good. Whilst everything is out, put a small blob of solder across the copper tape joints. The glue degrades over time and becomes less conductive.