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Extech readings


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5/9/2006 8:35 AM
Mick Extech readings
Anyone have info on what sort of readings I should be looking for from different types of pickups when using the extech 380193 ,  
thanks,  
Mick
 
5/12/2006 2:57 PM
Joe Gwinn

On 5/9/2006 2:35 PM, Mick said:  
quote:
"Anyone have info on what sort of readings I should be looking for from different types of pickups when using the extech 380193"
That's a pretty open-ended question. There are lots of pickup types around. What have you measured and what readings (inductance and AC resistance at 1 KHz) did you get? Maybe someone else has measured that too, and will be able to compare notes.
 
5/12/2006 3:40 PM
Greg Simon
On a related note to this thread Joe, I finally got the specs from my Rickenbacker 230 guitar with the samarium cobalt magnet pickups. I think it was you that was saying they would be interested in seeing the results a couple months back? I'll post them later tonight when I get home.  
 
Greg
 
5/13/2006 4:33 PM
Greg Simon
As promised, here is the info on my RIC 230 pickups. All measurements were made with the Extech meter, and with a nice quality Fluke DMM. The bridge and neck pickup are very close to each other so I think they are the same pickup. Here are the specs for the neck pickup.  
 
DCR = 14.45k  
 
@ 1 KHZ:  
 
ACR = 19.60k  
Q = 2.096  
Inductance = 6.801 henries  
 
@ 120 HZ:  
 
ACR = 14.55k  
Q = .3677  
Inductance = 6.959 henries  
 
These are a typical humbucker in design, but narrower and longer than your typical Gibson PAF. They're also epoxied so I couldn't get them apart without damaging them. They sound very good for hard rock and heavy metal stuff, in addition to rhythm playing for pop rock stuff. For lead tones, they work great too as long as you don't use blackface fender amps. They have a midrange that really sticks out compared to most pickups. They still sell these pickups on some of their models. I don't know what all the numbers tell me, but I do notice that the ACR numbes are pretty high. Maybe someone else can tell me how these numbers affect the sound as compared to a Strat pickup or something more normal.  
 
Greg
 
5/20/2006 5:08 PM
Joe Gwinn

On 5/13/2006 10:33 PM, Greg Simon said:  
[QUOTE]As promised, here is the info on my RIC 230 pickups. All measurements were made with the Extech meter, and with a nice quality Fluke DMM. The bridge and neck pickup are very close to each other so I think they are the same pickup. Here are the specs for the neck pickup.  
 
DCR = 14.45k  
 
@ 1 KHZ:  
 
ACR = 19.60k  
Q = 2.096  
Inductance = 6.801 henries  
 
@ 120 HZ:  
 
ACR = 14.55k  
Q = .3677  
Inductance = 6.959 henries[/QUOTE]Seven henries. How are the highs? What's the capacitance of your guitar cable (tested while disconnected from guitar and amp)?  

 
quote:
"These are a typical humbucker in design, but narrower and longer than your typical Gibson PAF. They're also epoxied so I couldn't get them apart without damaging them."
Another useful test is to measure the coils independently, if possible.  

 
quote:
"They sound very good for hard rock and heavy metal stuff, in addition to rhythm playing for pop rock stuff. For lead tones, they work great too as long as you don't use blackface fender amps."
What's the issue with the blackface amp? Any idea what's going on?  

 
quote:
"They have a midrange that really sticks out compared to most pickups. They still sell these pickups on some of their models. "
Midrange is emphasized. This maskes sense with the high inductance.  

 
quote:
"I don't know what all the numbers tell me, but I do notice that the ACR numbes are pretty high. Maybe someone else can tell me how these numbers affect the sound as compared to a Strat pickup or something more normal."
Actually, the AC resistance is very close to the DC resistance, so there isn't much eddy-current loading. The AC resistance cannot be less than the DC resistance, and the excess of AC resistance over the DC resistance is due to the eddy-current loading.

 
5/21/2006 1:37 AM
Greg Simon
Joe, the pickups are pretty bright actually, but they are pretty odd. They have lots of bass, lots of mids, and lots of trebles, but in a way the highs are harsh to a certain extent as compared with a Strat for example. I use flatwounds on this guitar to get rid of the shrillness and harshness, and I suspect the harshness is due to the samarium cobalt magnets.  
 
I measured them disconnected from the guitar with the DMM and Extech. They're narrower than your typical PAF, so they have more highs than a PAF due to the narrower coils, and a lot more mids than a PAF, and they also stay articulate when the gain is really turned up, kind of like a Firebird pickup, whereas a PAF might muddy up.  
 
With a blackface, they sound ok when clean, but if you try to play louder in a blackface amp, they just don't sound very good. I think it is due to the mid scoop that the blackface amps have, but I'm not certain. I just play them through a Vox AC30, Marshalls, Mesa Dual Rectifier, Supro Thunderbolt, Silvertone 1484 Twin Twelve, and it sounds fabulous. Jason Lollar has played this guitar once about 8 years ago or so through his Super Reverb and I remember him remarking on how loud they were. (wonder if he remembers?)  
 
They do have 4 conductor cable, but I'd have to take the pickups out of the connector that the wires are in and strip some wires back to see what each coil is and I don't feel like doing that. This guitar has a circuit board in it to hook everything up so its not as easy as normal stuff. The pickups are also epoxied and have a circuit board on the bottom of them. Pretty strange! I'm glad RIC doesn't do all their guitars this way, but I do like the pickups on this one.  
 
Greg
 
5/21/2006 5:45 PM
Joe Gwinn

On 5/21/2006 7:37 AM, Greg Simon said:  
quote:
"Joe, the pickups are pretty bright actually, but they are pretty odd. They have lots of bass, lots of mids, and lots of trebles, but in a way the highs are harsh to a certain extent as compared with a Strat for example. I use flatwounds on this guitar to get rid of the shrillness and harshness, and I suspect the harshness is due to the samarium cobalt magnets."
There seems to be very little eddy-current loading, which would tend to make the highs harsher. What other metal stuff is near the coils, and what kind of metal is it?  

 
quote:
"I measured them disconnected from the guitar with the DMM and Extech. They're narrower than your typical PAF, so they have more highs than a PAF due to the narrower coils, and a lot more mids than a PAF, and they also stay articulate when the gain is really turned up, kind of like a Firebird pickup, whereas a PAF might muddy up. "
I'm really curious to know the capacitance seen by the pickup, from the cable and amp. The Extech can measure this. The easy way is to get a open phone jack, unplug cable from guitar and plug into the open jack, clip Extech to the jack terminals, set Extech to C and d (capacitance and dissipation factor) and 1 KHz, nad measure away. The test signal from the Extech is something like one volt, and will not bother the amp, be it on or off. Pickup outputs are in the same voltage range.  
 
Anyway, given the capacitance and the inductance, we can compute the resonant frequency.  

 
quote:
"With a blackface, they sound ok when clean, but if you try to play louder in a blackface amp, they just don't sound very good. I think it is due to the mid scoop that the blackface amps have, but I'm not certain. I just play them through a Vox AC30, Marshalls, Mesa Dual Rectifier, Supro Thunderbolt, Silvertone 1484 Twin Twelve, and it sounds fabulous. Jason Lollar has played this guitar once about 8 years ago or so through his Super Reverb and I remember him remarking on how loud they were. (wonder if he remembers?)"
I'm guessing that the excess highs get chopped up when overdriving the amps, but the amps vary is how they handle chopped-up sound. It's hard to be more precise without some lab work.  

 
quote:
"They do have 4 conductor cable, but I'd have to take the pickups out of the connector that the wires are in and strip some wires back to see what each coil is and I don't feel like doing that. "
If one sets the volume control to max loud and the tone pot to put max resistance in series with the tone capacitor, one may be able to isolate things using the switch, depending on how it's wired.  

 
quote:
"This guitar has a circuit board in it to hook everything up so it's not as easy as normal stuff. The pickups are also epoxied and have a circuit board on the bottom of them. Pretty strange! I'm glad RIC doesn't do all their guitars this way, but I do like the pickups on this one."
I guess it was easier to manufacture that way.

 

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