Guys,
My understanding of some posts is that tube amps struggle with providing sufficient power for bass tones, mostly due to driver requiring more power than drivers for mid and high tones. Is that right?
If so, I was considering using one of the Yaqin pre-outs for my subwoofer.
This would allow me to pick some lighter book shelf style speakers to be driven by my Meng X1 amplifier.
For some who may not know, the Yaqin MS-12B has 2 outputs: a 0.25V output and a 0.7V output. I was considering using the 0.25V output for the subwoofer.
For info, the sub is an MJ Acoustics Reference I (first version) woofer.
Is this feasible, and does this actually make sense??
Basically I felt that using my CDM 7NT speakers on the Meng X1 Amp, with Yaqin MS-12B as pre-amp, didn't really cut it in the low range. On my ss system, those same speakers, combined with the woofer, are pretty amazing when playing SACD. I just miss that sense of space, and the low end when playing normal CD through the Meng X1.
Note: Turntable sounds a LOT better than normal CD through the tube amp setup.
Opinions please?
My understanding of some posts is that tube amps struggle with providing sufficient power for bass tones, mostly due to driver requiring more power than drivers for mid and high tones. Is that right?
If so, I was considering using one of the Yaqin pre-outs for my subwoofer.
This would allow me to pick some lighter book shelf style speakers to be driven by my Meng X1 amplifier.
For some who may not know, the Yaqin MS-12B has 2 outputs: a 0.25V output and a 0.7V output. I was considering using the 0.25V output for the subwoofer.
For info, the sub is an MJ Acoustics Reference I (first version) woofer.
Is this feasible, and does this actually make sense??
Basically I felt that using my CDM 7NT speakers on the Meng X1 Amp, with Yaqin MS-12B as pre-amp, didn't really cut it in the low range. On my ss system, those same speakers, combined with the woofer, are pretty amazing when playing SACD. I just miss that sense of space, and the low end when playing normal CD through the Meng X1.
Note: Turntable sounds a LOT better than normal CD through the tube amp setup.
Opinions please?
I typically use the speaker level inputs so that the sub amp gets some of the "flavor" of the amplifier.
dave
dave
I can understand that, but surely that will make the load on the amp worse, won't it?
My main reason is to get better low end without affecting the load on the amp.
My main reason is to get better low end without affecting the load on the amp.
My sub IS an active sub, otherwise I would not be able to connect it up via my yaqin ms-12b pre amp. I'm just wondering how good an idea that is...
The input impedance of the speaker inputs on a plate amp are typically 10k ohm plus...
10K in parallel with 4, 8, or 16 ohms is 4, 8, or 16 ohms.
dave
10K in parallel with 4, 8, or 16 ohms is 4, 8, or 16 ohms.
dave
Yes, you have an active sub, but that is a very different concept to an active crossover. Hooking up as you describe will work, however, with a little effort you can do much better.
The way you are describing your intended setup, you will still be sending the full range signal to the tube amp that is powering the bookshelf speakers. The amp is still trying to reproduce the low frequencies even thought the speakers will be incapable of reproducing them. The sub looks like it has a plate amp that most likely has a passive crossover...
An active crossover placed after the pre amp will use active components (transistors or valves) to split the signal in to high and low range. Highs go to your Meng X1, lows to the sub.
See this article BiAmp (Bi-Amplification - Not Quite Magic, But Close) - Part 1
ACtually, you can set the upper response frequency limit on the sub...
MJ Acoustics. Reference I Active Sub Bass System.
However, you are correct when you say that all frequencies go to the sub when using the LFE sockets. And external crossover would have to be in place if I were to use those connections as they expect low frequencies.
Considering bi-amping, I did actually consider this (and still do)
I did read the Bi-amp article, but some things are not too clear.
If I want to keep things simple (and lets forget about the sub woofer idea for the moment), I was considering splitting the output channels from the Yaqin pre. I.e. split the left channel into two output, run that to one Meng X1, and connect one to the Meng X1's left input and one to the Meng X1s Right input. Then I connect th Meng's Left channel to, say, high/mid poles on my speaker, and the right channel output to the Low poles on my speaker. Effectively one channel of the Meng would power mid+high drivers on one speaker, and one channel would drive the low driver on that same speaker (my speakers are bi-wirable).
This repeated for the other speaker with a second Meng X1.
What I don't know if it is acceptable to split one channel from the pre-out to two input channels on the Meng...
MJ Acoustics. Reference I Active Sub Bass System.
However, you are correct when you say that all frequencies go to the sub when using the LFE sockets. And external crossover would have to be in place if I were to use those connections as they expect low frequencies.
Considering bi-amping, I did actually consider this (and still do)
I did read the Bi-amp article, but some things are not too clear.
If I want to keep things simple (and lets forget about the sub woofer idea for the moment), I was considering splitting the output channels from the Yaqin pre. I.e. split the left channel into two output, run that to one Meng X1, and connect one to the Meng X1's left input and one to the Meng X1s Right input. Then I connect th Meng's Left channel to, say, high/mid poles on my speaker, and the right channel output to the Low poles on my speaker. Effectively one channel of the Meng would power mid+high drivers on one speaker, and one channel would drive the low driver on that same speaker (my speakers are bi-wirable).
This repeated for the other speaker with a second Meng X1.
What I don't know if it is acceptable to split one channel from the pre-out to two input channels on the Meng...
What I have done when I tweaked someone's Yaqin is take a tap off the speaker output. It has been amplified some 30 db, so you can make a divider. I did something like 20k/2k.
This then goes to one of the inputs that is unused. There you can link it with a cable. Best of course is do this in stereo. If you have one center bass only, then this needs to be summed.
It works satisfactory.
alberti
This then goes to one of the inputs that is unused. There you can link it with a cable. Best of course is do this in stereo. If you have one center bass only, then this needs to be summed.
It works satisfactory.
alberti
Since sub looks like it has a good active crossover, you want to stop the speaker powering your mains from working too hard trying to reproduce the low frequencies. I think active is best, but you can still reduce the low frequencies getting to the main amp with a simple capacitor/resistor network at the input of the main amp.
Here it goes. The drawing is not very nice as I now use Keynote which is not user friendly for this task.
It is just a few parts.
The cinch is of course not connected to the input selector anymore. That could send electrons round and round, aka oscillation! 😱
alberti
Attachments
Why would you want to do a setup like this? It will exacerbate any problem that the tube amp has powering low frequencies and will increase the noise to the sub. The best situation is to stop the lows getting to the tube amp to start with. An active filter will do this. Since he has such a filter on the sub, the full signal can be sent from the pre to the sub. You now want the signal from the pre to the tube amp to have the base taken away so that you are not wasting precious headroom in that amp trying to reproduce frequencies being processed by the sub. You can do this with an active high pass filter, but this will take a few opamps and another power supply. If this is seen as too complex, a simpler method would be to place a simple capacitor/resistor network at the input of the tube amp. Since the first stage of the tube amp will have a grid leak resistor, a simple capacitor in series with the input may be all that is required. See this site for a frequency calculator Guitar Pedals: R-C Filter Calculator
You are quite right that a pre-out is preferable.
But the YQ-MC5881 I worked on has no separate pre-aplifier stage. The Yaqin has an amplification factor of more than 40 dB (5k1 over 47 ohm). This is good for connecting an MP3 player like an iPod. But for normal use this is not OK.
And there is no point to take out the signal. That is why I devised this little tick. (It is the same way active speakers from Philips also were configured in the seventies and later: they had both a DIN input plug and a speaker-out input plug.)
alberti
Maybe I am confused. I thought the original question was how to use the two sets of pre-out on a Yaqin MS-12B pre-amp and how to best send that signal to his Meng X1 Amp and active sub. From his description there are two outputs on the pre-amp, a .25V output and a .7V output. Are you saying that the pre-out amplifies the signal too much to be useful? I would try the .25V output for the sub and see how well it integrates. If the signal level is too high for the sub, I would then look at padding it down.
Apologize! I should retract my posts. I was thinking of a different Yaqin equipment. Should have double checked.😱
alberti
Thanks guys,
So if I understand correctly, all I would need to do, is use a filter between the pre and the the X1 to eliminate the low tones, and I should be ready to go?
The freq calc from Chrish is very useful indeed. If I understand correctly this is a passive 1st order frequency, am I right? SHould I implement this filter between the pre and X1, or is it meant for between the X1 and the speakers?
So if I understand correctly, all I would need to do, is use a filter between the pre and the the X1 to eliminate the low tones, and I should be ready to go?
The freq calc from Chrish is very useful indeed. If I understand correctly this is a passive 1st order frequency, am I right? SHould I implement this filter between the pre and X1, or is it meant for between the X1 and the speakers?
Yes, this will be a first order passive crossover. Place it between the pre amp and the power amp. Determine the grid leak resistor on the input tube. You should be able to do this by using a multimeter between the ground and the signal contacts of the input RCA jack - with the amp turned off of course. The value will probably be something like 470K to 1M. This will be the resistance to ground in the filter. You can then determine what capacitor to place in series with the input to make the filter. You could do this externally if you did not want to re-wire anything inside the amp.
I don't know to what extend it matters, but my Meng X1 is not a power amp, but an integrated amp. At the moment I use the Yaqin pre-amp for phono pre only. I would imagine I can use the output of the Yaqin directly into the line in of the Meng X1 when using the yaqin as phono pre only, is that correct? I don't hear or notice anything strange with teh sound, so I imagine the Yaqin outputs a signal that can be used on a line in of any integrated amp.
Now for the tricky bit, If I want to do bi-amping using 2 Meng x1's (one for each side), I can imagine the voltage output from the Yaqin will drop if the output of the Yaqin is simply split to two receiving units (the two Meng's). Will this be a problem? I'd imagine it won't be considering the Yaqin has a 0.25 and a 0.7V output. If I use the 0.7V output, based on the logic I just described, the voltage for each Meng's line in would be 0.35V, which is still in the region of the Yaqin's output (0.25 and 0.7).
However, I could be missing the ball completely.
basically I was considering doing a direct split of the Yaqin 0.7V output, and sending each output via a passive crossover to the Meng units (each line having its own crossover). Then each meng would drive a speaker driver directly (for this I would probably build my own speakers, leaving out the crossover network).
Does this sound like a decent approach?
Now for the tricky bit, If I want to do bi-amping using 2 Meng x1's (one for each side), I can imagine the voltage output from the Yaqin will drop if the output of the Yaqin is simply split to two receiving units (the two Meng's). Will this be a problem? I'd imagine it won't be considering the Yaqin has a 0.25 and a 0.7V output. If I use the 0.7V output, based on the logic I just described, the voltage for each Meng's line in would be 0.35V, which is still in the region of the Yaqin's output (0.25 and 0.7).
However, I could be missing the ball completely.
basically I was considering doing a direct split of the Yaqin 0.7V output, and sending each output via a passive crossover to the Meng units (each line having its own crossover). Then each meng would drive a speaker driver directly (for this I would probably build my own speakers, leaving out the crossover network).
Does this sound like a decent approach?
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