Aria Sinsonido preamp repair
Moderator: Moderators
Aria Sinsonido preamp repair
Hi all,
A colleague of mine has an Aria Sinsonido silent bass guitar. For those who have never seen these things this is what they look like: http://www.ariauk.com/aria-as-691b-bass-guitar/ The pickup is a described as "Original Stereo Mic in Tube", and there is a volume and tone control.
In this case the tone control does not work. A local guitar shop took a look, and passed it to their electronics person. He looked at it and concluded the circuit board was damaged, but was unable to source a replacement or repair it. It's a small circuit board with what look like two ICs, a bunch of caps and resistors, and the pots soldered directly onto the board. If I can figure out how to post a picture I've got a decent pic which shows the components.
It's a good travel bass, still playable, and would be worth trying to repair, the question is where to start? Do we try to see if the whole board is dead, is there a suitable design that can be copied and fitted in? I'm long out of practice with electronics (like 30 years), but would be happy to have a go at building a new board. In fact I would prefer that to trying to repair the old one, as the old one still allows the guitar to be played
Many thanks as ever,
Rich
A colleague of mine has an Aria Sinsonido silent bass guitar. For those who have never seen these things this is what they look like: http://www.ariauk.com/aria-as-691b-bass-guitar/ The pickup is a described as "Original Stereo Mic in Tube", and there is a volume and tone control.
In this case the tone control does not work. A local guitar shop took a look, and passed it to their electronics person. He looked at it and concluded the circuit board was damaged, but was unable to source a replacement or repair it. It's a small circuit board with what look like two ICs, a bunch of caps and resistors, and the pots soldered directly onto the board. If I can figure out how to post a picture I've got a decent pic which shows the components.
It's a good travel bass, still playable, and would be worth trying to repair, the question is where to start? Do we try to see if the whole board is dead, is there a suitable design that can be copied and fitted in? I'm long out of practice with electronics (like 30 years), but would be happy to have a go at building a new board. In fact I would prefer that to trying to repair the old one, as the old one still allows the guitar to be played
Many thanks as ever,
Rich
My ambition: To one day have enough experience to answer technical questions on the SOS forums, as well as asking them
Re: Aria Sinsonido preamp repair
The forum doesn't host images so you'll need to host it somewhere else (imgur is currently a good bet) and then link to it here.
- Drew Stephenson
Forum Aficionado -
Posts: 24653 Joined: Sun Jul 05, 2015 12:00 am
Location: York
Contact:
(The forumuser formerly known as Blinddrew)
Ignore the post count, I still have no idea what I'm doing...
https://drewstephenson.bandcamp.com/
Ignore the post count, I still have no idea what I'm doing...
https://drewstephenson.bandcamp.com/
Re: Aria Sinsonido preamp repair
Right, the reason I couldn't post the image is because the corporate firewall wouldn't allow upload to imgur. Should have guessed that since almost all upload sites are blocked.
Here's a link: https://imgur.com/Bq5vDXa
Hopefully that works
Here's a link: https://imgur.com/Bq5vDXa
Hopefully that works
My ambition: To one day have enough experience to answer technical questions on the SOS forums, as well as asking them
Re: Aria Sinsonido preamp repair
Unfortunately knowing how to post a pic is where my useful contributions cease.
- Drew Stephenson
Forum Aficionado -
Posts: 24653 Joined: Sun Jul 05, 2015 12:00 am
Location: York
Contact:
(The forumuser formerly known as Blinddrew)
Ignore the post count, I still have no idea what I'm doing...
https://drewstephenson.bandcamp.com/
Ignore the post count, I still have no idea what I'm doing...
https://drewstephenson.bandcamp.com/
Re: Aria Sinsonido preamp repair
Hi Dr. R,
It ought to be worth contacting Aria to see if they would provide you with a circuit diagram, but even if they're not forthcoming, someone with a little more electronic experience could trace out the circuit diagram by viewing the other side of that circuit board - this circuit doesn't look too complicated.
Even those two ICs have visible part numbers on them (well they would be visible under a magnifying glass ), so those could be replaced if they are the faulty parts.
Martin
It ought to be worth contacting Aria to see if they would provide you with a circuit diagram, but even if they're not forthcoming, someone with a little more electronic experience could trace out the circuit diagram by viewing the other side of that circuit board - this circuit doesn't look too complicated.
Even those two ICs have visible part numbers on them (well they would be visible under a magnifying glass ), so those could be replaced if they are the faulty parts.
Martin
- Martin Walker
Moderator -
Posts: 20642 Joined: Wed Jan 13, 2010 8:44 am
Location: Cornwall, UK
Contact:
Re: Aria Sinsonido preamp repair
Hi Martin,
Aria's support page starts off :
"Welcome to our Support page for your Aria guitar.
Please note we are unable to provide information on the following:
Serial Numbers, Instrument Valuations, Wiring Diagrams"
And then tells you all the things that aren't covered under their limited lifetime warranty.
Rich
<edit>. ps. With squinting at the photo (the guitar isn't to hand) and a bit of Googling, the chips are probably LM386 audio amps. If there is one per microphone, with the tone control varying the balance between the two then I can see how that would work.
Aria's support page starts off :
"Welcome to our Support page for your Aria guitar.
Please note we are unable to provide information on the following:
Serial Numbers, Instrument Valuations, Wiring Diagrams"
And then tells you all the things that aren't covered under their limited lifetime warranty.
Rich
<edit>. ps. With squinting at the photo (the guitar isn't to hand) and a bit of Googling, the chips are probably LM386 audio amps. If there is one per microphone, with the tone control varying the balance between the two then I can see how that would work.
My ambition: To one day have enough experience to answer technical questions on the SOS forums, as well as asking them
Re: Aria Sinsonido preamp repair
LM386's are power amps so they're unlikely to be used here. Someone experienced could almost certainly trace out the circuit diagram but my first instinct would be to find out what is hiding under that insulating tape - that looks a bit like a bodged repair.
- James Perrett
Moderator -
Posts: 14379 Joined: Mon Sep 10, 2001 12:00 am
Location: The wilds of Hampshire
Contact:
JRP Music - Audio Mastering and Restoration. JRP Music Facebook Page
Re: Aria Sinsonido preamp repair
James Perrett wrote:LM386's are power amps so they're unlikely to be used here.
Oh, hadn't realised that. I found this page, with the chip running off a 9v battery, so I took that as evidence that my squinting was OK: http://www.circuitbasics.com/build-a-great-sounding-audio-amplifier-with-bass-boost-from-the-lm386/
I didn't think the bass has been repaired. I'll need to ask the owner. Unless he reads this forum, joins, and decides to post
My ambition: To one day have enough experience to answer technical questions on the SOS forums, as well as asking them
Re: Aria Sinsonido preamp repair
It should be quite straightforward. I doubt those chips are anything special, but we'd definitely need to know exactly. We'd also need to see the underside of the board. There may be quite a bit of stuff under there.
I would guess that to gain access, you take off the pot knobs, then undo the retaining nuts and the whole thing comes out. It's a pity the leads are soldered to the board and not plugged, otherwise I'd say send it to me!
I would guess that to gain access, you take off the pot knobs, then undo the retaining nuts and the whole thing comes out. It's a pity the leads are soldered to the board and not plugged, otherwise I'd say send it to me!
- Folderol
Jedi Poster -
Posts: 18223 Joined: Sat Nov 15, 2008 12:00 am
Location: The Mudway Towns, UK
Contact:
Yes. I am that Linux nut {apparently now an 'elderly'}
Onwards and... err... sideways!
Onwards and... err... sideways!
Re: Aria Sinsonido preamp repair
http://www.ti.com/lit/ds/symlink/lm386.pdf
Look like 386's to me and the chip (not a proper 'op amp' BTW) is very suited to this task as it only draws 4mA and is pretty near bomb-proof.
Yes the lekkie's tape looks naff but is only on the battery supply and since the board works the wires must be ok. Worth looking at though.
You can prove both chips work pretty surely by measuring the output pin voltages, should be close to 4.5V for a 9V supply. As it is the tone that does not work I suspect an O/C pot track or an SMT component dropped off, maybe tother side of the PCB?
Dave.
Look like 386's to me and the chip (not a proper 'op amp' BTW) is very suited to this task as it only draws 4mA and is pretty near bomb-proof.
Yes the lekkie's tape looks naff but is only on the battery supply and since the board works the wires must be ok. Worth looking at though.
You can prove both chips work pretty surely by measuring the output pin voltages, should be close to 4.5V for a 9V supply. As it is the tone that does not work I suspect an O/C pot track or an SMT component dropped off, maybe tother side of the PCB?
Dave.
Re: Aria Sinsonido preamp repair
Many thanks all!
The instrument is under my desk at work, so on Monday we'll see how easy it is to take the pots off and photograph the other side of the board. I'll take in a multimeter and measure the voltages as well.
Have a great weekend everyone, and thanks again.
Rich
The instrument is under my desk at work, so on Monday we'll see how easy it is to take the pots off and photograph the other side of the board. I'll take in a multimeter and measure the voltages as well.
Have a great weekend everyone, and thanks again.
Rich
My ambition: To one day have enough experience to answer technical questions on the SOS forums, as well as asking them
Re: Aria Sinsonido preamp repair
I've just blown up the photo and turned it by 180 degrees, and it does seem to read LM386:
Also, are we sure that this black stuff is insulating tape, and not a blob of some rubbery substance that's designed to hold that battery cable safely in place onto the circuit board?
Martin
Also, are we sure that this black stuff is insulating tape, and not a blob of some rubbery substance that's designed to hold that battery cable safely in place onto the circuit board?
Martin
- Martin Walker
Moderator -
Posts: 20642 Joined: Wed Jan 13, 2010 8:44 am
Location: Cornwall, UK
Contact:
Re: Aria Sinsonido preamp repair
Very puzzling. That would seem to be totally inappropriate for the job it's doing
- Folderol
Jedi Poster -
Posts: 18223 Joined: Sat Nov 15, 2008 12:00 am
Location: The Mudway Towns, UK
Contact:
Yes. I am that Linux nut {apparently now an 'elderly'}
Onwards and... err... sideways!
Onwards and... err... sideways!
Re: Aria Sinsonido preamp repair
The PCB traces seem to back up the idea that it is an LM386 in inverting mode too.
I missed the bit where the fault was mentioned on my first read through. If the tone control isn't working could it be as simple as a dodgy joint on a capacitor?
I missed the bit where the fault was mentioned on my first read through. If the tone control isn't working could it be as simple as a dodgy joint on a capacitor?
- James Perrett
Moderator -
Posts: 14379 Joined: Mon Sep 10, 2001 12:00 am
Location: The wilds of Hampshire
Contact:
JRP Music - Audio Mastering and Restoration. JRP Music Facebook Page
Re: Aria Sinsonido preamp repair
From memory the black stuff is rubbery gunk at the end of the power leads.
Hope to post photos of the back of the board and more info tomorrow.
Hope to post photos of the back of the board and more info tomorrow.
My ambition: To one day have enough experience to answer technical questions on the SOS forums, as well as asking them
Re: Aria Sinsonido preamp repair
Hi again,
Here are better photographs of the circuit board. Top, bottom and edge on. I've taken quite large photographs, so hopefully there is enough detail.
The black stuff is an epoxy gunk, no obvious reason for it that I can see. Removing the board would be desoldering eight wires from the PCB and cutting the battery wires further up.
I wasn't able to make any voltage measurements at lunchtime, but will do so tomorrow. Any other measurements that can be done with a multimeter and a little headphone amp, let me know
Many thanks to everyone who has replied to this. My colleague's comment "What an amazing board - the forum not the circuit" says a lot.
Rich
Here are better photographs of the circuit board. Top, bottom and edge on. I've taken quite large photographs, so hopefully there is enough detail.
The black stuff is an epoxy gunk, no obvious reason for it that I can see. Removing the board would be desoldering eight wires from the PCB and cutting the battery wires further up.
I wasn't able to make any voltage measurements at lunchtime, but will do so tomorrow. Any other measurements that can be done with a multimeter and a little headphone amp, let me know
Many thanks to everyone who has replied to this. My colleague's comment "What an amazing board - the forum not the circuit" says a lot.
Rich
My ambition: To one day have enough experience to answer technical questions on the SOS forums, as well as asking them
Re: Aria Sinsonido preamp repair
Is the pot on the right the tone control?
- James Perrett
Moderator -
Posts: 14379 Joined: Mon Sep 10, 2001 12:00 am
Location: The wilds of Hampshire
Contact:
JRP Music - Audio Mastering and Restoration. JRP Music Facebook Page
Re: Aria Sinsonido preamp repair
James Perrett wrote:Is the pot on the right the tone control?
According to the manual on the Aria worldwide archive http://ariaguitarsglobal.com/wp-content/uploads/Sinsonido-instructions.pdf the tone control is the one on the right looking at the pots end on from the outside, as James suggests.
I'll have to actually plug it in tomorrow and check because I can't remember.
My ambition: To one day have enough experience to answer technical questions on the SOS forums, as well as asking them
Re: Aria Sinsonido preamp repair
Report back from the investment bank guitar workshop. Getting some strange looks at lunchtime now
Numbering the pins according to the photograph above as
2, 4, 6
1, 3, 5
with 1, 3, 5 closest to the shaft.
Pot A (volume).
Rich
- The volume pot is the one closest to the thicker white lead going to the output (marked A on the back), the tone control is the other one (B).
- Testing with the multimeter showed a voltage out Vout-GND of around 0.5-0.6V when the E string is plucked. Same for both chips, independent of the volume out position.
Numbering the pins according to the photograph above as
2, 4, 6
1, 3, 5
with 1, 3, 5 closest to the shaft.
Pot A (volume).
- R12 = 1.96K, regardless of position
- R13 14 Ohm - 1.1K variable
- R12 = 1.2K, regardless of position
- R13 11 Ohm regardless of position
Rich
My ambition: To one day have enough experience to answer technical questions on the SOS forums, as well as asking them
Re: Aria Sinsonido preamp repair
Is it a dual ganged pot and, if so, have you checked the other half (pins 2, 4 and 6?
- James Perrett
Moderator -
Posts: 14379 Joined: Mon Sep 10, 2001 12:00 am
Location: The wilds of Hampshire
Contact:
JRP Music - Audio Mastering and Restoration. JRP Music Facebook Page