Hi Everyone,
I just got the new release of the full kit Whammy. I'm reviewing the current build guide and see that only the power entry module and RCA connectors are attached to the chassis ground screw. Just wondering if this is correct.
I just got the new release of the full kit Whammy. I'm reviewing the current build guide and see that only the power entry module and RCA connectors are attached to the chassis ground screw. Just wondering if this is correct.
I was trying to understand how the pcb is connected to ground. I thought it would be a direct connection from the pcb to ground, but I guess I'm mistaken.
Sorry for the dumb question, but what are these new boards? I can't seem to find it looking back through the thread...
Aren't the RCA grounds connected to the board as well?
As I recall, the circuit ground gets connected to chassis ground through a safety cap.
They are just my own "DIY" version of the WHAMMY. My main objective was to make the boards smaller and much less costly to order. Reducing the size and cost should make DIY of the WHAMMY possible for many more people. A few little mods were made like class A bias of the opamp output stage, provisions for the Burson opamp, input/output/connector/potentiometer options, input cap size options, use of Panasonic FM caps, etc.
An important change (for me) was to enable different chassis size/form factors and different (external) power supplies. An aluminum chassis can be much less expensive with a smaller board. For example, I plan to try my version with the low noise "LF353 Servo" LM317/LM337, the super regulator and then two different shunt supplies that I already have. Later I plan to make my own PCB for a discrete power supply regulator like the one used in the Pass Labs HPA-1.
I also made my own DIY layout of the Pass Labs HPA-1. When the PCB arrive I will be busy assembling and comparing the HPA-1 and the WHAMMY.
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Hello,
I finished building the Whammy last week (store kit) and this week I am trying out a couple of alternate op amps. I have a few questions I am hoping to get some feedback on.
1) I built the LED regulator configuration. My voltage when I tested the PSU without a load was right around +17.0x -17.0x volts. Burson says max on the two I am trying are 16.5 volts. Is this something to worry about or would the supply voltage drop with load?
2) What is a safe level of DC offset? On the V5i I am getting 0 mV on one channel and 1.6 mV on the other channel. With the V6 Classic it starts off at a high of around 18 mV on each channel when I turn the unit on, then eventually drops to around 0.9 and 2.x mV.
3) The plastic case of the V6 Classic touches the sides of the surrounding capacitors. It gets pretty warm. Do I need to rejiggle things so the caps are not touching the plastic case?
Thanks!
By the way, I've only briefly listened to the alternate op amps, but the Whammy with the V6 Classic sounds beautiful into the HD 650.
I finished building the Whammy last week (store kit) and this week I am trying out a couple of alternate op amps. I have a few questions I am hoping to get some feedback on.
1) I built the LED regulator configuration. My voltage when I tested the PSU without a load was right around +17.0x -17.0x volts. Burson says max on the two I am trying are 16.5 volts. Is this something to worry about or would the supply voltage drop with load?
2) What is a safe level of DC offset? On the V5i I am getting 0 mV on one channel and 1.6 mV on the other channel. With the V6 Classic it starts off at a high of around 18 mV on each channel when I turn the unit on, then eventually drops to around 0.9 and 2.x mV.
3) The plastic case of the V6 Classic touches the sides of the surrounding capacitors. It gets pretty warm. Do I need to rejiggle things so the caps are not touching the plastic case?
Thanks!
By the way, I've only briefly listened to the alternate op amps, but the Whammy with the V6 Classic sounds beautiful into the HD 650.
I have not had any problem with the Burson op-amps, and my voltage is the same.
Most people have found the Classic to be much better than the Vivid in this amp. If you can, you might try to SparkOS op-amp. It's wonderful!
Most people have found the Classic to be much better than the Vivid in this amp. If you can, you might try to SparkOS op-amp. It's wonderful!
Sorry to "rain on your parade" guys but Burson states that 16.5 v are the MAXIMUM voltage, not 17 or whatever - this is their design set limit, not an arbitrary value, for a very good reason - it's a credit to their build quality that they'll tolerate this continual overvoltage condition but why would you intentionally operate any device beyond their MAX specifications?
An analogy is to continuously run an engine over maximum design limits and not expect component failure. Why risk failure of these excellent but expensive opamps?
The simplest way to reduce the opamp +/- rails (separate from the main regulators) would be to replace the R35/R36 (47R) resistors with another pair of +/- 15 volt regulators, or a simple cap multiplier, on an extra bit of vero board - you can find a 0volt point on the 220uF cap next door - there appears to be plenty of room around the R35/R36 resistor position on the diyA pcb to do this
An analogy is to continuously run an engine over maximum design limits and not expect component failure. Why risk failure of these excellent but expensive opamps?
The simplest way to reduce the opamp +/- rails (separate from the main regulators) would be to replace the R35/R36 (47R) resistors with another pair of +/- 15 volt regulators, or a simple cap multiplier, on an extra bit of vero board - you can find a 0volt point on the 220uF cap next door - there appears to be plenty of room around the R35/R36 resistor position on the diyA pcb to do this
The spec sheet I'm reading says 17V. But, in any event, you're aware that Burson offered op-amps, on this very thread, to people to test with the Whammy? Mine came directly from them, in response to that invitation. They've even got a picture on their website of a Whammy with a V6 Classic.
It's possible, I guess, that they didn't bother to check that the op-amps were suitable, but I doubt it.
It's possible, I guess, that they didn't bother to check that the op-amps were suitable, but I doubt it.
PSU resistors/LED
Hi all.
The text on the schematic diagram says to ommit R9+R13 when building the LED reference config. But in the build guide, R10+R14 are also not soldered in. What is correct? To me, it makes sense to ommit all four.
Regards, Klaus
Hi all.
The text on the schematic diagram says to ommit R9+R13 when building the LED reference config. But in the build guide, R10+R14 are also not soldered in. What is correct? To me, it makes sense to ommit all four.
Regards, Klaus
Has anyone ever tried to increase the value of R35/R36 in order to lower the operating voltage for the opamp leaving the rails at 17 V (LED reference). I found a thread with the proposal to do so but nothing about the result.
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Burson is already in "safe" area when using LED reference. My measurements were the same as @Martigane in post #4251 above.
I wanted to have some "air" to the max. specification that from memory was -+16.5V. I remember that V6 draws a lot more current than specified. That helped a bit to reduce the voltage. Think that it is the heat generated that determines the max voltage and my whammy gets a bit hot so I just wanted to be 100% safe and sleep good at night 🙂
It was also based on advices that there were no reason to run an expensive op-amp at max specifications. I think back in the thread.....long time ago.....I showed my measurements etc.....
It was also based on advices that there were no reason to run an expensive op-amp at max specifications. I think back in the thread.....long time ago.....I showed my measurements etc.....
Really liked it. Compact plate, with potentiometer and earphone jack included. Practical and easy to assemble. Congratulations.
My question was not related to the burson opamps. I am running the vivid in my first whammy build with LED ref. without any issues. Rails are at 16.9 V, burson sees 16.4 V due to the relatively high current consumption. That‘s just perfect. And its extremely quiet with wonderful audio quality.
In my actual build I want to use the Muses02 or Muses8920. For both of the them, different specs are published. So I was concerned about max operating voltage. I contacted NJR and they were so kind to give me the correct values. So to stay within the parameters I hand-selected two red LED‘s with only 1.6 V forward voltage. As a result, rails are at 16.6.
0.2 V drop due to the current consumption > 16.4 for the muses which is perfectly within the spec.
In my actual build I want to use the Muses02 or Muses8920. For both of the them, different specs are published. So I was concerned about max operating voltage. I contacted NJR and they were so kind to give me the correct values. So to stay within the parameters I hand-selected two red LED‘s with only 1.6 V forward voltage. As a result, rails are at 16.6.
0.2 V drop due to the current consumption > 16.4 for the muses which is perfectly within the spec.
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