I have two (OC Electronics Type 56 Foldline Reverberation Devices)
They have the Z type spring arrangement, both the Input & Output DC resistance of the coils is around 172 Ohms.
One Coil is Yellow & the other is Red, I am trying to determine which is the Input & the Output?
Does anyone know the Input Impedance Specs or have the Datasheet info they could share or a link etc?.
Cheers
They have the Z type spring arrangement, both the Input & Output DC resistance of the coils is around 172 Ohms.
One Coil is Yellow & the other is Red, I am trying to determine which is the Input & the Output?
Does anyone know the Input Impedance Specs or have the Datasheet info they could share or a link etc?.
Cheers
Thanks dumptruck,
Yes, I have read that somewhere else as well, I will check things out with accutronics as you mentioned.
Cheers
Not much.
Keeping in mind that DC resistance is not impedance, and looking at the chart of Accutronics specs, I'd have to think that 172 ohms DC means these are on the high impedance end of the reverb scale. For Accutronics that would mean about 1500 ohms.
Since reverb pans all work the same way, I feel reasonably comfortable comparing the two brands
The pan needs a drive of like 3-5ma.
Look up just about ANY Peavey amplifier with reverb and you will find a single 4558 dual op amp driving and recovering the reverb pan. Pretty simple, and it works. I have seen some that add a couple little push pull transistors to assist the op amp, but they are typically nothing more than 2N3904/3906.
Also, go to the Accutronics web site, and they have some suggested circuits to drive their reverb pans. You should be able to adapt those with little or no modification.
And if you are going to roll your own reverb, you generally cut out the low end of the audio fed to it. Low freq notes don;t reverb well, and mostly just make the sound muddy.
Keeping in mind that DC resistance is not impedance, and looking at the chart of Accutronics specs, I'd have to think that 172 ohms DC means these are on the high impedance end of the reverb scale. For Accutronics that would mean about 1500 ohms.
Since reverb pans all work the same way, I feel reasonably comfortable comparing the two brands
The pan needs a drive of like 3-5ma.
Look up just about ANY Peavey amplifier with reverb and you will find a single 4558 dual op amp driving and recovering the reverb pan. Pretty simple, and it works. I have seen some that add a couple little push pull transistors to assist the op amp, but they are typically nothing more than 2N3904/3906.
Also, go to the Accutronics web site, and they have some suggested circuits to drive their reverb pans. You should be able to adapt those with little or no modification.
And if you are going to roll your own reverb, you generally cut out the low end of the audio fed to it. Low freq notes don;t reverb well, and mostly just make the sound muddy.
Thanks Enzo,
Yes, I have noticed the 4558 dual op amps in my Amp, it's a Peavey Classic Chorus 130 stereo series.
I am building a small Tube-Valve drive & recovery for these reverb pans, for a small amp I am building, it's an interesting project so I will see how I go.
I think your correct in that you can compare different brands, there's not much difference in the way they operate.
I see what your saying with cutting the low end, it makes perfect sense.
Thanks for the advice & the tips, much appreciated.
Cheers
Yes, I have noticed the 4558 dual op amps in my Amp, it's a Peavey Classic Chorus 130 stereo series.
I am building a small Tube-Valve drive & recovery for these reverb pans, for a small amp I am building, it's an interesting project so I will see how I go.
I think your correct in that you can compare different brands, there's not much difference in the way they operate.
I see what your saying with cutting the low end, it makes perfect sense.
Thanks for the advice & the tips, much appreciated.
Cheers
tube reverb
My H100 organ drives the Hammond reverb tank with a 7247 tube with a 500 ohm choke on the plate to 275V B+, and a 1000 ohm resistor from the cathode to ground. The input is a EF86 tube with about 7000 mhos sensitivity. The schematic is in the Hammond H100 service manual on archive.org. Figure 41, upper right. (upper left since it is turned sideways). I was reading about 8v PP out, and about 25 mv back in with my 20 mhz scope.
My H100 organ drives the Hammond reverb tank with a 7247 tube with a 500 ohm choke on the plate to 275V B+, and a 1000 ohm resistor from the cathode to ground. The input is a EF86 tube with about 7000 mhos sensitivity. The schematic is in the Hammond H100 service manual on archive.org. Figure 41, upper right. (upper left since it is turned sideways). I was reading about 8v PP out, and about 25 mv back in with my 20 mhz scope.
They make the various impedance pans for a reason. the op amp circuit like in the Peavey amps expects the high impedance input to drive. The other end of the scale is the transformer driven reverbs like Fender has used for decades. These are typically tube driven by a small single ended stage driving the pan through a transformer. Those usually drive the low impedance input pans. COnsidering the high impedance of your imput stage, I wouldn't think it was expecting a transformer drive.
Look at some old Ampeg circuits, they used a high impedance pan and drive it off the plate of a drive tube through a cap.
Look at some old Ampeg circuits, they used a high impedance pan and drive it off the plate of a drive tube through a cap.
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