Rockett 10 Tone Hammer  [traced]

General documentation, gut shot, schematic links, ongoing circuit tracing, deep thoughts ... all about boutique stompboxes.
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Manfred
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Post by Manfred »

10ToneHammerComponetsSide.jpg
10ToneHammerSolderSide.jpg
It was difficult to trace the PCB, a measurement using an ohmmeter was often necessary.
The PCB got more than two layers.
10ToneHammer.JPG
Rockett10ToneHammerClippingDiodes.jpg

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mirosol
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Post by mirosol »

Guys at the tagboardeffects blog have built this and there is one slight error in the schem. The 10K from bass pot's lug 1 should most likely connect to ground instead of 1/2V. Having it at 1/2V means that the dc voltage will reach recovery FET's gate and this will make the bass pot work iffy. Gavin just moved the resistor to ground and his tonestack now works as intended.
+m
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Manfred
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Post by Manfred »

mirosol wrote:Guys at the tagboardeffects blog have built this and there is one slight error in the schem. The 10K from bass pot's lug 1 should most likely connect to ground instead of 1/2V. Having it at 1/2V means that the dc voltage will reach recovery FET's gate and this will make the bass pot work iffy. Gavin just moved the resistor to ground and his tonestack now works as intended.
+m
Thanks for the hint.
I was very surprised that the 10kOhm resistor is connected to the 1/2V and I rechecked the connection, it was right.
Maybe I'm simply was wrong or the fault came from Rockett, but I have no way of confirming this, because I sold the pedal.
I am annoyed with myself, because I usally read the voltages on the FET's pins, this time I forgot it.
But anyway, the pedal seems to be working well with the resistor connection to the ground.

I attach the corrected schematic:
10ToneHammer_2.JPG

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Manfred
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Post by Manfred »

I checked the FET-stage by circuit simulation.
Sorry, that was my fault regarding the 10 Kiloohms resistor connection to half voltage point.
The resistor must indeed connect to the ground.
If the resistor is conntected to the half voltage point the bias point of the FET-stage is floating depending on Bass pot setting.
BTW, the almost same stage is applied in the Rockett Flex Drive circuit.
The simulation resulted in a value of 5V at the drain.

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Post by Säröpedaali »

Should 1k+100n and 1k+220n to pin 2 to go ground?

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Manfred
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Post by Manfred »

Säröpedaali wrote:Should 1k+100n and 1k+220n to pin 2 to go ground?
It is indeed connected as shown in the schematic.
In the AC equivalent network, the half voltage point is equivalent to the power supply ground.

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Post by Säröpedaali »

Manfred wrote:
Säröpedaali wrote:Should 1k+100n and 1k+220n to pin 2 to go ground?
It is indeed connected as shown in the schematic.
In the AC equivalent network, the half voltage point is equivalent to the power supply ground.
Ok. I build this in breadboard and it's oscillating high pitch like crazy:).

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Post by alltrax »

Check your breadboard I built it and it sounds great

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charvel502
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Post by charvel502 »

I also have a ton of oscillation after building it from the effects layouts site, maybe because its not boxed yet....?

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Post by charvel502 »

fixed my oscillation issue, swapped the 100pF off of pin 2 for a 220pF, was able to adjust the J201 to 4.5v with no oscillation.

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