A cool repair! Thanks for salvaging that gem! I used to have two refin pre-eb's but I found them too heavy on my shoulder on long gigs. Now I have a 2010 2-band 'Ray that is lighter. I have also found that I prefer the sound of the newer lighter alder bodies to the old heavy ash bodies.
Cheers mate. Yes, this bass was fairly heavy. The ash is fairly hefty, but I think the old steel bridges with string mutes and those two big bolts and threaded bushings are a big part of the weight too. Had a killer tone though...
Watching your videos make me regret selling my 2011 Sterling Ray34CA. If I remember correctly, the preamp was a replica of the 77's preamp. Such a beautiful bass! Amazing content, Rob.
Another job and repair executed perfectly rob, well done. I’ve got a Wal Mk2 1982 in for repair, some fairly standard fretwork but it also has some preamp problems that I’m not looking forward to. Those preamps have got some extra wizardry going on!!! 😂😂
@@RobMods yeah they are very similar to the alembic stuff. Alembic has a few more bells and whistles in a lot of cases. This bass just has a blend control with an individual LP filter for each pickup, also each pickup has its own 10dB boost. Very similar to ACG basses made here in Scotland.
Hi. Just a question: Potentiometers type A is for volume and type B is for tone? My Ibanez bass has type B500K for pickups volume and D500K for Tone and I'm confused
In passive guitars, generally both volume and tone pots are audio taper (A). However, linear taper (B) are also often used as volume, especially with larger value like 500k and 1meg. That's because the actual sweep of the pot also depends on the impedance that follows. Is your ibanez an older instrument? D was often used to indicate log and audio taper with certain pot manufacturers. During the 90s A for log and audio tapers seemed to become the standard.
I bought my first brand new bass in 1978. I had a choice between a Stingray or Precision. I went for an all maple Precision which I still own. The Stingray was a relatively new bass and everyone I seen on the Old Grey Whistle Test had Fenders. Prior to that I had been playing a Gibson EB? which had one pickup.
Great video Rob! I have a 1980 MMSR that seems to have an issue in the pre amp. Treble gets distorted above 50%. Can you share that schematic with me so I can share it with my luthier and try to fix my preamp? Thanks so much!
Can I have your advice please , Im building a bass with 2 Delano MC4 HE/S dual coil MM pickups , i want the bass to be passive , I bought 2 x toggle switches 2 positions . this will give me hopefully a single and double coil options with each pickup, I have noticed people are putting 3 position switches , for Series , parallel ,phase ,. To be honest I don't really understand what this witchcraft means , should i be buying 3 way switches for the witchcraft options is it better than single double on each pickup will I get more tonal option . Thanks .
For a bass, I wouldn't bother with out of phase sounds. They usually sound tinny and with low output. I would go with single/series/parallel switches. This is what Music Man does with the 3-way blade switch on their basses. You will get a louder output with the series setting, but you'll have three quite different and useful tones. You'll need "on-on--on" toggle switches, which aren't cheap though. Best of luck with the project mate!
Great video... My bass of similar age, seems to create a sound like a boom when I try to lower the volume... Does it just once and then no noises till I keep playing a song or two, try to lower the volume and there you are the crackling boom again... Sound like a capacitor to me... Any ideas?
It's hard to say without seeing the instrument, but I'd check all the normal stuff - battery snap, output jack, pots etc. But yeah, if that output coupling cap has shorted, then the vol control will be passing a tiny amount of DC, which, over time may well lead to the symptoms you've outlined, and a faulty pot. Honestly though, this is a 45 year old circuit board. There could be dry joints, corroded wires, caps and resistors with micro cracks etc. The value of these instruments continues to climb and people really want originality. If you aren't that confident with vintage through-hole stuff, perhaps consider removing and conserving the original pre, and putting in a new clone, for reliability. I'd do this, especially if you are gigging and touring with this bass... They are great instruments. Best of luck!
That schematic that’s online didn’t match some of the preamps I’ve examined. There’s a modified schematic floating around that I corrected. It is notated “FIXED 9-7-11.” The 220k resistor in the feedback loop is usually 100k. Also you can improve the slew rate a bit by changing the programming resistor at pin 8 to 2M2. It will draw a bit more current. The schematic you showed has it at 1M5. Originally the output jack didn’t switch off the battery. It was on all the time!
Nice seeing you around the tubes, David! I am wondering why the resistor needed replacing in this case; since it was metered at 1M8 it should have been closed to the 2M2 as you suggest?
I'm afraid I don't know any luthiers in NY. I always suspect the simple stuff first, especially the electro-mechanical parts (jacks, battery snaps, switches, pots... in that order). This video proves that sometimes it's a deeper problem unfortunately. But by far the most common reason for a dead onboard pre is a damaged output jack. Remember it not only carries the signal, but also switches on the preamp. Even just a loose jack can cause problems, if it has spun and its contacts are shorting on shielding paint for example. Bad battery snaps or contacts are also a surprisingly common problem. Best of luck with the trouble shooting man!
I'm from Brazil, and I have a 1978 epoxy stingray. The treble potentiometer is squeaking when turned, and when I close it all the way the bass sound doesn't come out anymore. I already changed the potentiometer for another (C1M) and the problem continues. Do you think it could be a problem with the preamp? PS: When the treble potentiometer is in the middle and I don't touch it, the bass sound comes out perfectly.
Without seeing your pre in person it's impossible to diagnose, but perhaps the input cap or the two treble pot caps have failed. If the input cap has failed it is probably like the output cap in this video. Tantalum caps tend to fail to a short. I would test the dc at the input with the pickup removed and the treble pot in the centre. There should be no dc here, since the input coupling cap should block the dc path from the inverting input of the op amp. If you measure a voltage then try a cap between the pickup hot and the pre input. (1uF - 10uF non polar). If the problem persists, then yes perhaps the treble caps have failed.
Great content! I'm also a bass player and I've started out doing repairs to instruments. I resently restored a 1973 Precision Bass, and I've noticed that the output jack is sometimes cutting out because it is contacting the walls of the rout. Is this something you've experienced? Greetings from Sweden
Hi Johan, Yes this is a common problem. Either the contact is shorting on shielding paint/tape, or it is simply fouling on the timber and the contact is not flexing properly. It happens on strats a lot as well. If you have the original '73 celluloid pickguard, it has probably shrunk and buckled as well, which might be part of the problem. These little problems are all part of the fun!
i was just messing around with my '94(?) G&L bass and saw something that reminded me of this video. ol' leo must have been a stubborn guy. still no battery switching on the jack. even though there's specifically a switching mono jack installed (not a TRS jack)... that 3rd pin has never seen any solder 🤷♂
Great video!!. I have a StingRay Erni ball from 1992 and the input jack attached to the electronics produces a lot of noise, and a luthier did not know how to repair it. Then they ruined the pickup by adding glue, in an attempt to insert the sharp magnets. I was thinking on buying a Sterling SUB because of the 2 band preamp, and the Sterling StingRay 34 because of the alnico pickup. Do you think thats a good option or maybe I should buy John East 2 band preamp + Aguilar pick up?
The preamps I build sound better than the stock preamp. I use the LT1351 and get rid of the 1M5 resistor at pin 8. The sound is amazing with more detailed highs and mids
Yes this preamp can be improved in many ways, with modern parts and other tweaks. I'm guessing the 4250 has a very limited slew rate when that pin 8 resistor is set so high. I often wonder if pickup and pre designs would have been so radical, if Fender and his engineers had realized that simple trick with the stereo jack...
Carbon resistors drifting like that is kind of unusual unless there's a lot of current going through them, in which case they can become damaged due to excessive heat... Some older carbon resistors could be damaged by mechanical shock too... IC front ends can be damaged by electrostatic discharge, but I'd say the thing to check first in a circuit like that would be the caps... Tantalum capacitors of that vintage had a tendency to short out; it was a common problem. Replacements are cheap, if that were my bass, I would just replace all of the tantalums.
Yep, I agree, I don't know why this one was so far off. More than 20% IIRC. As for the tants, the owner was adamant I keep as much original as possible. But for me, yep, I'd replace them if it were mine... (Actually with the value of these nowadays, I'd probably just put the pre safely in a draw and put in a copy circuit!) In the other video I have repairing an old 'ray, the output coupling cap was short. Thanks for your comments!
This is a diy musician's gold mine! Thanks for the top class content!
Cheers Sean!
A cool repair! Thanks for salvaging that gem! I used to have two refin pre-eb's but I found them too heavy on my shoulder on long gigs. Now I have a 2010 2-band 'Ray that is lighter. I have also found that I prefer the sound of the newer lighter alder bodies to the old heavy ash bodies.
Cheers mate. Yes, this bass was fairly heavy. The ash is fairly hefty, but I think the old steel bridges with string mutes and those two big bolts and threaded bushings are a big part of the weight too. Had a killer tone though...
Watching your videos make me regret selling my 2011 Sterling Ray34CA. If I remember correctly, the preamp was a replica of the 77's preamp. Such a beautiful bass! Amazing content, Rob.
Thanks mate.
Thank you! And wow, really great bass playing at the end of this video Rob! Nice harm. min. and an exceptional touch you have on bass..!
Another job and repair executed perfectly rob, well done.
I’ve got a Wal Mk2 1982 in for repair, some fairly standard fretwork but it also has some preamp problems that I’m not looking forward to. Those preamps have got some extra wizardry going on!!! 😂😂
Yes, I think they are similar to the Alembic stuff with the state variable filter design. Best of luck with the repair!
@@RobMods yeah they are very similar to the alembic stuff. Alembic has a few more bells and whistles in a lot of cases. This bass just has a blend control with an individual LP filter for each pickup, also each pickup has its own 10dB boost. Very similar to ACG basses made here in Scotland.
Hi. Just a question: Potentiometers type A is for volume and type B is for tone? My Ibanez bass has type B500K for pickups volume and D500K for Tone and I'm confused
In passive guitars, generally both volume and tone pots are audio taper (A). However, linear taper (B) are also often used as volume, especially with larger value like 500k and 1meg. That's because the actual sweep of the pot also depends on the impedance that follows. Is your ibanez an older instrument? D was often used to indicate log and audio taper with certain pot manufacturers. During the 90s A for log and audio tapers seemed to become the standard.
I bought my first brand new bass in 1978. I had a choice between a Stingray or Precision. I went for an all maple Precision which I still own. The Stingray was a relatively new bass and everyone I seen on the Old Grey Whistle Test had Fenders. Prior to that I had been playing a Gibson EB? which had one pickup.
Thanks, I also have a 78 stingray. It came wired so the battery was always on , something to do with the switch on jack. Where are you based?
Great video Rob! I have a 1980 MMSR that seems to have an issue in the pre amp. Treble gets distorted above 50%. Can you share that schematic with me so I can share it with my luthier and try to fix my preamp? Thanks so much!
The schematic is on my website, here: robkiddhomepage.wixsite.com/robkiddmusic/rob-mods-yt-extras Best of luck with the repairs.
@@RobMods Would you build one of these preamps?
Can I have your advice please , Im building a bass with 2 Delano MC4 HE/S dual coil MM pickups , i want the bass to be passive , I bought 2 x toggle switches 2 positions . this will give me hopefully a single and double coil options with each pickup, I have noticed people are putting 3 position switches , for Series , parallel ,phase ,.
To be honest I don't really understand what this witchcraft means , should i be buying 3 way switches for the witchcraft options is it better than single double on each pickup will I get more tonal option . Thanks .
For a bass, I wouldn't bother with out of phase sounds. They usually sound tinny and with low output. I would go with single/series/parallel switches. This is what Music Man does with the 3-way blade switch on their basses. You will get a louder output with the series setting, but you'll have three quite different and useful tones. You'll need "on-on--on" toggle switches, which aren't cheap though. Best of luck with the project mate!
Thanks Rob for taking the time to get back to me appreciated .@@RobMods
Great video...
My bass of similar age, seems to create a sound like a boom when I try to lower the volume...
Does it just once and then no noises till I keep playing a song or two, try to lower the volume and there you are the crackling boom again...
Sound like a capacitor to me...
Any ideas?
It's hard to say without seeing the instrument, but I'd check all the normal stuff - battery snap, output jack, pots etc. But yeah, if that output coupling cap has shorted, then the vol control will be passing a tiny amount of DC, which, over time may well lead to the symptoms you've outlined, and a faulty pot. Honestly though, this is a 45 year old circuit board. There could be dry joints, corroded wires, caps and resistors with micro cracks etc. The value of these instruments continues to climb and people really want originality. If you aren't that confident with vintage through-hole stuff, perhaps consider removing and conserving the original pre, and putting in a new clone, for reliability. I'd do this, especially if you are gigging and touring with this bass... They are great instruments. Best of luck!
That schematic that’s online didn’t match some of the preamps I’ve examined. There’s a modified schematic floating around that I corrected. It is notated “FIXED 9-7-11.” The 220k resistor in the feedback loop is usually 100k.
Also you can improve the slew rate a bit by changing the programming resistor at pin 8 to 2M2. It will draw a bit more current. The schematic you showed has it at 1M5.
Originally the output jack didn’t switch off the battery. It was on all the time!
Nice seeing you around the tubes, David! I am wondering why the resistor needed replacing in this case; since it was metered at 1M8 it should have been closed to the 2M2 as you suggest?
Rob, i'm an Aussie living in the USA but i need some questions answered about my Sterling by MM SB14.... HELP PLEASE!!!
I have a music man bongo that’s completely dead. Any advice ? Or Lutheran you can point me to in New York or the states ?
I'm afraid I don't know any luthiers in NY. I always suspect the simple stuff first, especially the electro-mechanical parts (jacks, battery snaps, switches, pots... in that order). This video proves that sometimes it's a deeper problem unfortunately. But by far the most common reason for a dead onboard pre is a damaged output jack. Remember it not only carries the signal, but also switches on the preamp. Even just a loose jack can cause problems, if it has spun and its contacts are shorting on shielding paint for example. Bad battery snaps or contacts are also a surprisingly common problem. Best of luck with the trouble shooting man!
@@RobMods thanks rob ! I’ve already replaced the output jack but the battery snaps is something I didn’t think of. You’re the man !
I'm from Brazil, and I have a 1978 epoxy stingray. The treble potentiometer is squeaking when turned, and when I close it all the way the bass sound doesn't come out anymore. I already changed the potentiometer for another (C1M) and the problem continues. Do you think it could be a problem with the preamp?
PS: When the treble potentiometer is in the middle and I don't touch it, the bass sound comes out perfectly.
Without seeing your pre in person it's impossible to diagnose, but perhaps the input cap or the two treble pot caps have failed. If the input cap has failed it is probably like the output cap in this video. Tantalum caps tend to fail to a short. I would test the dc at the input with the pickup removed and the treble pot in the centre. There should be no dc here, since the input coupling cap should block the dc path from the inverting input of the op amp. If you measure a voltage then try a cap between the pickup hot and the pre input. (1uF - 10uF non polar). If the problem persists, then yes perhaps the treble caps have failed.
@@RobMods Thanks for your help!!!
Great content! I'm also a bass player and I've started out doing repairs to instruments. I resently restored a 1973 Precision Bass, and I've noticed that the output jack is sometimes cutting out because it is contacting the walls of the rout. Is this something you've experienced? Greetings from Sweden
Hi Johan, Yes this is a common problem. Either the contact is shorting on shielding paint/tape, or it is simply fouling on the timber and the contact is not flexing properly. It happens on strats a lot as well. If you have the original '73 celluloid pickguard, it has probably shrunk and buckled as well, which might be part of the problem. These little problems are all part of the fun!
i was just messing around with my '94(?) G&L bass and saw something that reminded me of this video. ol' leo must have been a stubborn guy. still no battery switching on the jack. even though there's specifically a switching mono jack installed (not a TRS jack)... that 3rd pin has never seen any solder 🤷♂
Wow, really? That's very strange. I'd be warming up the soldering iron I reckon...
Great video!!. I have a StingRay Erni ball from 1992 and the input jack attached to the electronics produces a lot of noise, and a luthier did not know how to repair it. Then they ruined the pickup by adding glue, in an attempt to insert the sharp magnets. I was thinking on buying a Sterling SUB because of the 2 band preamp, and the Sterling StingRay 34 because of the alnico pickup. Do you think thats a good option or maybe I should buy John East 2 band preamp + Aguilar pick up?
The preamps I build sound better than the stock preamp. I use the LT1351 and get rid of the 1M5 resistor at pin 8. The sound is amazing with more detailed highs and mids
Yes this preamp can be improved in many ways, with modern parts and other tweaks. I'm guessing the 4250 has a very limited slew rate when that pin 8 resistor is set so high. I often wonder if pickup and pre designs would have been so radical, if Fender and his engineers had realized that simple trick with the stereo jack...
Carbon resistors drifting like that is kind of unusual unless there's a lot of current going through them, in which case they can become damaged due to excessive heat... Some older carbon resistors could be damaged by mechanical shock too... IC front ends can be damaged by electrostatic discharge, but I'd say the thing to check first in a circuit like that would be the caps... Tantalum capacitors of that vintage had a tendency to short out; it was a common problem. Replacements are cheap, if that were my bass, I would just replace all of the tantalums.
Yep, I agree, I don't know why this one was so far off. More than 20% IIRC. As for the tants, the owner was adamant I keep as much original as possible. But for me, yep, I'd replace them if it were mine... (Actually with the value of these nowadays, I'd probably just put the pre safely in a draw and put in a copy circuit!) In the other video I have repairing an old 'ray, the output coupling cap was short. Thanks for your comments!
Hola, help me please !!!
From Chile, e-mail ?
🙏🙏🙏