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Old 6th January 2012, 08:53 PM   #21
azvrt is offline azvrt  Netherlands
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The bias must not exceed 25 mvdc (or 30 at the very, very most) on this particular model or the amp could damage itself. The bias on 3.0 / 6.0 is much higher but they are different amps.

I have 4 Ref Picasso boards, on all these boards the bias can be set way over 25 mvdc by turning the pots. This should be avoided but the reason I am saying it is that I find it very strange that your board cannot be turned higher than 19 mvdc. Something is not quite right. But like Perry said, you might not be able to hear the difference between 19 mvdc and 25 mvdc.
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Old 7th January 2012, 12:51 AM   #22
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my rail voltage is +/- 23v with bench 12v power supply i remember it should be +/- 35v?
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Old 7th January 2012, 12:56 AM   #23
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what should the bias be for reference 6.0 i'm currently setting mines at 25mv. if i was to raise it what will it change? the amp never gets hot or even warm. same thing with the picasso never gets hot or warm.
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Old 7th January 2012, 09:34 AM   #24
azvrt is offline azvrt  Netherlands
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At 25 mvdc, I can imagine the 6.0 never gets hot.
It must be set between 80 mvdc and 140 mvdc.

At 25 mvdc the idling current will be very low (how much is it ?) and yes the amplifier won't get hot. At the right bias setting the amplifier should idle around 3 ampere (at 12 volts) and then it will get warm at 4 ohms stereo and HOT at lower impedances.
I find it strange you can set it as low as 25 mvdc, I had a 6.0 and could not set it lower than 57 mvdc. I set it that low as mine was idling way too high.
How much power supply voltage are you feeding the amps ? Measure at the positive and negative terminal of the amp, not at the power supply / battery, please.

At 4 ohms stereo a Picasso won't get hot as its idling current with bias properly set is 1.4 ampere only (at 12 volts).
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Old 7th January 2012, 07:00 PM   #25
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Below is the final test spec for the Picasso direct from the manufacturer. It is a direct cut and paste so please refer any and all questions to the manufacturer. This should answer most of your questions though and clear any electronic fog that may be giving you cause to question.



1. Set DC Power Supply to 13V. Install 25Amp fuse.

2. Connect Power and Ground to amplifier. Confirm unit is off. Connect Remote; note instant turn on of power supply. Confirm Idle Current of less than 1 Amp.

3. Confirm rails of 21.2V. (+/- 1V)

4. Set bias to 20mV. (+/- 5mV) Verify DC Offset of 15mV or less.

5. Connect input signal to RCA inputs. Connect 4-Ohm load to output. Input 300mV and verify output of 10Vrms. Adjust input level if necessary to get 10Vrms. Note that the input level should be 300mV +/- 10mV. Change input level to 500mV. Verify clip LED has come ON. Check all channels. Return to 300mV level.

6. Check Frequency response: Flat +/- 0.5dB 20Hz to 20kHz. THD: Less than 0.1% 20Hz-2kHz, 0.15% @ 20kHz. Repeat for other channel. (80kHz filter in)

7. Measure Signal-to-noise @ 2kHz 80dB or better ( 80kHz and 400Hz filters in)

8. Shutdown test: Momentarily short each output. Confirm amplifier shuts down and turns back on.

9. Input to RIGHT channel. Set level to produce 10Vrms across 4 Ohm mono. Switch to MONO and verify 20Vrms out. Repeat for channels 3&4. Return switch to STEREO.
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Old 7th January 2012, 07:39 PM   #26
azvrt is offline azvrt  Netherlands
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Are you certain this is not for the Rubicon Picasso ?
Jaime told me that ideally the bias for the Reference Picasso is 25 mvdc and 20 mvdc for the Rubicon Picasso (and Renoir).

1 ampere idling seems low for Reference Picasso. The boards I have tested so far all had around 1.3 / 1.4 at 12 volts already. The Rubicon Renoir indeed has less than 1 ampere, around 0.9 ampere to be precise. Unfortunately I haven't owned a Rubicon Picasso up till now so I don't know its idling current.

Thanks for sharing the info !
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Old 8th January 2012, 02:17 AM   #27
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will i hear a difference in sound quality if i was to replace the emitter resistor with same value but with film type, wirewound, metal foil, metal oxide, etc. if this will affect sound quality which resistor type will give me the best sound quality. i like spacious, separation, wide soundstage, and to hear performer take a breath. what must i do to get this.
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Old 8th January 2012, 04:12 PM   #28
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There will be no difference in sound quality. There's essentially nothing that you can do to this amp to make it sound better (produce cleaner output) than it did with the original parts (assuming that all were in proper working order).
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Old 9th January 2012, 01:14 AM   #29
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you broke my heart Mr. Babin, thanks for telling me the truth and for me to stop wasting my time changing parts in hopes of a better sounding amp. i will be taking a break from car audio for a bit. don't worry you will see me again.
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Old 9th January 2012, 04:09 AM   #30
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Before you can solve a problem, you have to determine what that problem is. What, precisely, don't you like about the sound from this amplifier?
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