The 9 volt limit is usually due to the driver chip operating voltage rails and distortion considerations of the driver chip.
Plus I also have never seen a reason for any higher voltage output. Most amps like JL and such have a 9 volt range selection for their input gain circuitry so it can accommodate such unusually high drive levels.
Please remember that every amp I have ever seen also has a input buffer just to manage very low signal levels. The high drive level is useful to over come high noise levels in most cases.
Most home and commercial gear only requires a 1 volt signal to drive the amp to full power depending on how you set the gains. Setting a amp at minimum gains will allow you to use a high drive level, but here again it is for noise issues not dynamic musical enhancement.
If you really need higher voltage then you should look into balanced line drivers. Some of them can output up to 14 volts and up, but these are used in sets a transmitter and a receiver to recover a usable signal for a standard RCA input to use. Unless you using certain amps like Zapco high end series , and SoundStream Ref and Rub series and the like. These all have a balanced input on them to allow for the use of Professional rated balanced line driver gear.
Unless you have a specific noise related or input compensation need for high drive levels, I would not even use a line driver. They will just most likely overload your inputs on your amps and cause all sorts of issues on system setup.
Plus I also have never seen a reason for any higher voltage output. Most amps like JL and such have a 9 volt range selection for their input gain circuitry so it can accommodate such unusually high drive levels.
Please remember that every amp I have ever seen also has a input buffer just to manage very low signal levels. The high drive level is useful to over come high noise levels in most cases.
Most home and commercial gear only requires a 1 volt signal to drive the amp to full power depending on how you set the gains. Setting a amp at minimum gains will allow you to use a high drive level, but here again it is for noise issues not dynamic musical enhancement.
If you really need higher voltage then you should look into balanced line drivers. Some of them can output up to 14 volts and up, but these are used in sets a transmitter and a receiver to recover a usable signal for a standard RCA input to use. Unless you using certain amps like Zapco high end series , and SoundStream Ref and Rub series and the like. These all have a balanced input on them to allow for the use of Professional rated balanced line driver gear.
Unless you have a specific noise related or input compensation need for high drive levels, I would not even use a line driver. They will just most likely overload your inputs on your amps and cause all sorts of issues on system setup.
An amplifier in it's simplest form is just a voltage multiplier.
Voltage out = gain x voltage in.
Max output voltage is limited by the specific amplifier design, so an input voltage higher than what the amp is designed for won't result in more power output.
Using a 9V line driver, you could conceivably add a high current voltage follower (gain = 1) and get about 20 watts/4ohms without even using an amp...
Voltage out = gain x voltage in.
Max output voltage is limited by the specific amplifier design, so an input voltage higher than what the amp is designed for won't result in more power output.
Using a 9V line driver, you could conceivably add a high current voltage follower (gain = 1) and get about 20 watts/4ohms without even using an amp...
You guys seem really smart.
I am not really sure that I posted in the correct section, if not, please redirect me.
My initial post above was just an "observation" on my part.
My design project reads as follows:
Project:
Design a 12 volt preamp which has an output voltage that is variable from 1 - 30 volts RMS, unbalanced.
I am not really sure that I posted in the correct section, if not, please redirect me.
My initial post above was just an "observation" on my part.
My design project reads as follows:
Project:
Design a 12 volt preamp which has an output voltage that is variable from 1 - 30 volts RMS, unbalanced.
David Navone has a home audio preamp from QuickSilver audio that has a 65 volts output voltage, but it is almost $4,000.00.
Here is an excerpt from the QuickSilver site:
Full Function Preamplifier
Quicksilver's new phono-inclusive preamp is a technical tour de force. Mike Sanders' unique design delivers the pure tube sound Quicksilver is known for, without the limitations common in other tube preamps. The high output impedance common with tube preamps can cause problems when mating to many solid state amplifiers. The ultra-low 1.5 Ohm output impedance of the Full Function preamp allows it to drive any amplifier known and using virtually any length or type of cabling.
Sonic performance is maximized through the use of extremely short signal paths, minimal switching and no transistors, regulators or circuit boards. A massive power supply resides in a isolated subchassis within the main preamp.
Hand wired, point to point circuitry
Passive and active RIAA Phono Equalization
Ultra low 1.5 Ohm output impedance
18dB Gain - Line, 47dB - Phono
Line Tubes: 2 x 12AX7, 2 x 6H30
Phono Tubes: 1 x 12AX&, 1 x 6N1P
60 V Maximum Output
17"W x 5.25"H x 11"D
Handcrafted in the U.S.A.
$3200
What is something like the above used for?
Here is an excerpt from the QuickSilver site:
Full Function Preamplifier
Quicksilver's new phono-inclusive preamp is a technical tour de force. Mike Sanders' unique design delivers the pure tube sound Quicksilver is known for, without the limitations common in other tube preamps. The high output impedance common with tube preamps can cause problems when mating to many solid state amplifiers. The ultra-low 1.5 Ohm output impedance of the Full Function preamp allows it to drive any amplifier known and using virtually any length or type of cabling.
Sonic performance is maximized through the use of extremely short signal paths, minimal switching and no transistors, regulators or circuit boards. A massive power supply resides in a isolated subchassis within the main preamp.
Hand wired, point to point circuitry
Passive and active RIAA Phono Equalization
Ultra low 1.5 Ohm output impedance
18dB Gain - Line, 47dB - Phono
Line Tubes: 2 x 12AX7, 2 x 6H30
Phono Tubes: 1 x 12AX&, 1 x 6N1P
60 V Maximum Output
17"W x 5.25"H x 11"D
Handcrafted in the U.S.A.
$3200
What is something like the above used for?
Because he can?
Seriously, I have no idea why someone would need that.
It's sort of a solution looking for a problem...
And, believe me, it sells. That is not a new design. Quicksilver Audio has been making those things for many years.
David Navone has always advocated that there is no subsitute for a high signal at the source, whether it be car audio, home audio or pro audio.
Just an excerpt:
"In car audio, home audio, and pro audio, there is no substitute for a source with a high signal level output. All factors equal, the deck with the highest signal level will always provide optimal performance. The Quicksilver audio in David's home listening room is capable of 65 volts of signal with a source impedance of less than 100 ohms. This is a good preamp."
SQ ABSOLUTE, the following rant is NOT directed at you. Your questions are appreciated.
Output voltage is nothing more than a design parameter.
That preamp may be a wonderful performer for many reasons. As for the output voltage, look at the quoted gain of 18dB for the line stage. In linear terms, that's about an 8x increase. So to get 60V out, the source signal would need to be around 7.5V (unless there is an additional gain stage not mentioned.) What's a typical home audio piece's output, 1V or so? The preamp may be capable of 60V output, but that doesn't mean it's what you'll get, or what you need.
If a large output voltage was the end-all performace indicator for hifi, all of the high end preamps would have had been doing it for the last 40 years.
Such misleading, egotistical, all-encompassing, statements began to abound in car audio magazines in the late 80's. I got so sick of reading the BS that I finally cancelled my subscription in '92. The cool pictures and factual information weren't worth my raised blood pressure over the BS.
The most volatile aspect of a car audio system is (and has been since high-quality amplifiers became common) how the speaker system is handled. Driver selection, integration, loading, placement, and EQ/crossover tuning. But if you listened to these "definitive" magazine writers, all you'd need is a line driver and $500 worth of Dynamat (or whatever the flavor of the month happened to be) to turn an off-the-shelf system into a top-notch performer.
Plenty of that printed garbage was Navone's drivel, too. You can be perfectly successful in your audio world -personally or professionally without listening to a word he says.
Now I don't doubt for a minute that Navone's listening room sounds fantastic, but it ain't because his preamp can produce a 60V output signal.
Sorry for the rant, I'll hush now.
Because he can?
Seriously, I have no idea why someone would need that.
It's sort of a solution looking for a problem...
I think I found the reason for such a device (preamp), based on my research.
Believe it or not, there are still a lot of phonograph (turntable) enthusiasts out there for those of you who can remember that far, that still use that kind of equipment as a playing source. I have found that on a SHURE Pro Audio Audiophile Phonograph Cartridge we are talking about 4.0 mV RMS at 1 kHz. That's .004 volts. Now multiply that small of a voltage x 65 and that puts you at .26 volts, if I can still count, to feed into another preamp or an amplifier.
I can now see the use of such a device, but I had to go back in time.
I think I found the reason for such a device (preamp), based on my research.
Believe it or not, there are still a lot of phonograph (turntable) enthusiasts out there for those of you who can remember that far, that still use that kind of equipment as a playing source. I have found that on a SHURE Pro Audio Audiophile Phonograph Cartridge we are talking about 4.0 mV RMS at 1 kHz. That's .004 volts. Now multiply that small of a voltage x 65 and that puts you at .26 volts, if I can still count, to feed into another preamp or an amplifier.
I can now see the use of such a device, but I had to go back in time.
Well, welcome to today. The front-end designs are better (with the help of better parts), these days, and CMRR is also much better. Just because something is there, doesn't mean that you need to use it. I am a strong advocate for "Less is Better". More parts from deck to speakers means more noise and more THD. It is possible that these values are small enough to be imperceptible, by the listener, but it is there. As it is with pro-gear, guitar-cord-amp!
And yes, viva la vinyl
Cheers
And if you'll look back at the gain of the Quicksilver's phono stage, it's 47dB. That's about 225x, so the .004V cartridge signal is increased to about 0.9V for the preamp.
If you want to see some beautiful work, visit the Analogue Source Forum. The DIY turntables and arms are works of passion, it's wonderful to see how many vinyl enthusiasts are around.
As for your own project, visit the Analog Line Level forum with questions and be prepared to procure or build a switching power supply to run it.
Thanks for redirecting me to the proper forum.
Also thanks to everyone for their input.
I think I found the reason for such a device (preamp), based on my research.
Believe it or not, there are still a lot of phonograph (turntable) enthusiasts out there for those of you who can remember that far, that still use that kind of equipment as a playing source. I have found that on a SHURE Pro Audio Audiophile Phonograph Cartridge we are talking about 4.0 mV RMS at 1 kHz. That's .004 volts. Now multiply that small of a voltage x 65 and that puts you at .26 volts, if I can still count, to feed into another preamp or an amplifier.
I can now see the use of such a device, but I had to go back in time.
A phono preamp also does RIAA equalization, so it's not quite the same thing as a pure line driver
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.