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.
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.
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).
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).
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.
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.
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 !
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 !
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.
I feel bad for Russdeanlee. I know how frustrating it can be when you are looking for a certain type of sound. The problem he is having with the Picasso I have experienced twice.
At some point I sold a Class A 3.0 and 6.0 to someone who absolutely loved them. He later also bought a Reference Picasso from me which is definitely a cleaner amplifier than the previous two. While he agreed on that he missed a certain warmth to the sound.
The sound of the Ref Picasso technically is closer to perfection than the 3.0 and 6.0, but technically perfect sound sometimes just doesn't do it for a person.
And I experienced the same thing. While the Reference Picasso is very, very clean, it just didn't do it for me on my mids due to the fact its sound is not warm enough for me (I like the sound on my mids very, very warm).
I therefore chose to put my Genesis Series 2 Class A's (which resemble the 3.0 / 6.0 more than they do the Picasso) on my mids as the combination with my Altec car speakers really does it (for me). The Picasso is absolutely perfect for the tweeters.
At some point Russdeanlee mentioned to me he missed warmth in the sound of the Picasso so maybe the story above is also the case for him.
Same things with my Renoirs (basically the same as a Ref Picasso). They are absolutely near-perfect and outperform my Genesis Series 2 high-bias amps, but nonetheless I prefer the Genesis on my mids. The near-perfection of the Renoirs doesn't do it for me there, so I use them bridged on bass speakers that operate in the 60 to 100 Hz frequency range, and like the Picasso they absolutely shine on tweeters.
I wish you all the best in your search for the sound that is pleasing to you and you only.
In the end, no two pairs of ears are the same and we all have our own brain and emotion.
By the way you might need to look at your speakers and head-unit as well. If I remember correctly you are using Dynaudio speakers. While I love the tweeters (especially on the Picasso), the woofers never did it for me, on any amplifier. In the end I put very old Altec Lansing M400 4 inch speakers in between the tweeters and the woofers and turned them into a three way, the Dynaudio woofers serving only as bass speakers from 60 Hz to 100 Hz.
The sound definitely improved.
Head-units will also produce different sound. A friend of mine and myself are both using an Eclipse CD8445E head-unit and CD-3083 CD Changer. The HU has a 24-bit DAC while the CD-Player has a 1-bit DAC. Since I installed the changer I NEVER use the head unit's internal CD player anymore as I absolutely prefer the sound the changer produces. My friend on the other hand prefers the head unit's internal player, on most recordings.
So for you to find YOUR perfect sound, many factors come into play. Use the right amp on the right speakers (highs/mids/bass/subs) and get some good recordings, so many crap recordings out there, which a revealing amplifier like a Picasso paired with Dynaudio speakers will only bring fully to your attention.
Since I have been improving the sound in my car, less and less recordings are pleasing to me. The good ones now sound fantastic and much better than before, but slightly less good ones sound pretty horrible...
Good luck ! And if you need to take a break so you can clear your mind and rest your emotions in order to have a fresh start, do it.
At some point I sold a Class A 3.0 and 6.0 to someone who absolutely loved them. He later also bought a Reference Picasso from me which is definitely a cleaner amplifier than the previous two. While he agreed on that he missed a certain warmth to the sound.
The sound of the Ref Picasso technically is closer to perfection than the 3.0 and 6.0, but technically perfect sound sometimes just doesn't do it for a person.
And I experienced the same thing. While the Reference Picasso is very, very clean, it just didn't do it for me on my mids due to the fact its sound is not warm enough for me (I like the sound on my mids very, very warm).
I therefore chose to put my Genesis Series 2 Class A's (which resemble the 3.0 / 6.0 more than they do the Picasso) on my mids as the combination with my Altec car speakers really does it (for me). The Picasso is absolutely perfect for the tweeters.
At some point Russdeanlee mentioned to me he missed warmth in the sound of the Picasso so maybe the story above is also the case for him.
Same things with my Renoirs (basically the same as a Ref Picasso). They are absolutely near-perfect and outperform my Genesis Series 2 high-bias amps, but nonetheless I prefer the Genesis on my mids. The near-perfection of the Renoirs doesn't do it for me there, so I use them bridged on bass speakers that operate in the 60 to 100 Hz frequency range, and like the Picasso they absolutely shine on tweeters.
I wish you all the best in your search for the sound that is pleasing to you and you only.
In the end, no two pairs of ears are the same and we all have our own brain and emotion.
By the way you might need to look at your speakers and head-unit as well. If I remember correctly you are using Dynaudio speakers. While I love the tweeters (especially on the Picasso), the woofers never did it for me, on any amplifier. In the end I put very old Altec Lansing M400 4 inch speakers in between the tweeters and the woofers and turned them into a three way, the Dynaudio woofers serving only as bass speakers from 60 Hz to 100 Hz.
The sound definitely improved.
Head-units will also produce different sound. A friend of mine and myself are both using an Eclipse CD8445E head-unit and CD-3083 CD Changer. The HU has a 24-bit DAC while the CD-Player has a 1-bit DAC. Since I installed the changer I NEVER use the head unit's internal CD player anymore as I absolutely prefer the sound the changer produces. My friend on the other hand prefers the head unit's internal player, on most recordings.
So for you to find YOUR perfect sound, many factors come into play. Use the right amp on the right speakers (highs/mids/bass/subs) and get some good recordings, so many crap recordings out there, which a revealing amplifier like a Picasso paired with Dynaudio speakers will only bring fully to your attention.
Since I have been improving the sound in my car, less and less recordings are pleasing to me. The good ones now sound fantastic and much better than before, but slightly less good ones sound pretty horrible...
Good luck ! And if you need to take a break so you can clear your mind and rest your emotions in order to have a fresh start, do it.
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OK so I have a picasso amp as well and tonight I went to check to bias V on each channel. They were all about .040V or 40mV. This is pretty much double what it should be set at from what I have been told and what I see on this posts. The thing is that this amp does not warm up, I am using it on a pair of DE500 + minibodies. There is nothing wrong with the sound either. So should I be worried about this? I put the amp back together and left it alone.
I know that this amp isn't an F5 but my F5 is biased at .60V. Why does the Piccasso need to be at .020V? Is thermal runaway the only problem? If so couldn't we just add some thermal compensation or shutoff
I know that this amp isn't an F5 but my F5 is biased at .60V. Why does the Piccasso need to be at .020V? Is thermal runaway the only problem? If so couldn't we just add some thermal compensation or shutoff
Hi my friend, I see you took my advise and moved your questions from Diyma over to this website.
However, people prefer you start a new thread when it concerns another unit, even if it is the same model. By the way, I believe your amp is a Rubi Picasso, this thread concerns a Ref Picasso.
Anyway, I started a new thread for you here, hope you don't mind:
http://www.diyaudio.com/forums/car-audio/207317-rubicon-picasso-questions.html#post2917554
And mentioned what we have discussed and done so far.
However, people prefer you start a new thread when it concerns another unit, even if it is the same model. By the way, I believe your amp is a Rubi Picasso, this thread concerns a Ref Picasso.
Anyway, I started a new thread for you here, hope you don't mind:
http://www.diyaudio.com/forums/car-audio/207317-rubicon-picasso-questions.html#post2917554
And mentioned what we have discussed and done so far.
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