a tube EQ survey

If you were to consider buying a tube equalizer, would you go for a mono or stereo version.
I would be very much interested in what you all would prefer, thank you.

Ok people, this is not a trick question   ......... how about some votes.......  

Need an option for wouldn't consider an eq under any circumstances.

thanks for the input, but this is a no option question, if you would not consider an EQ = no vote :-)

Montana,
Are you considering a mono version because it's just one channel giving you guff? I'd look into speaker placement or maybe an xover tweak before adding more stuff into the signal path.

I would not buy an EQ either

I think you may be going over the top with this  add-on. Why not outlet covers, Bybee quantum filters, etc? (Listed as snake oil on the diytube site.)

a cautionary tale:

At one time,I bought a Marchand PM-9 discreet, electronic crossover to improve the overall performance of my system. It did just that, but added a slight SS coloration,so I removed it. It now sits idle.

Marchand xover

(I just can't part with the electronics.)

You should also buy an SPL meter and signal generator to affirm your suspicions.

Then there's room treatment, suggested here an Deckkert's ideas

pmarcin wrote:I think you may be going over the top with this  add-on. Why not outlet covers, Bybee quantum filters, etc? (Listed as snake oil on the diytube site.)

You neglected to mention the new unobtanium power cables for sale now; $25,000/ft and IEC connectors are extra. guaranteed to improve frequency response curves past the 200,000 Hz level (at 1 watt, of course).

You also need an option for DSP equalization. This IS the nineties, after all ...

(and that's why we don't do polls)   

The bigger question is, graphic or parametric? Graphics tend to be limited as any slider adjustment also affects the surrounding frequencies and bandwidth. Parametric on the other hand allows you to dial the "Q" and address a specific problem in both center frequency AND bandwidth. A really good parametric allows you to stack filters so that you can attack a wide range while also tweaking a narrow band located inside that range.

DSP eq is relatively new, but now well within the realm of DIY home use. The software approach allows you to build as many filters as you need to flatten the spectrum, and even allows you to add room curves (think "smiley face") with the click of a button. Bit of a learning curve, but well worth the effort.

PS ... I've become something of an expert on eq over the years ...

Graphic (Stack 1 of 2)



Parametric



And finally, DSP ... it's all software based, so here's a pic of the test setup.



And yes - don't expect to be able to get anything but close trying to do it by ear. You need a good tone generator, SPL meter, calibrated microphone, mixer, and a sharp pencil to get it right. Even then, you're bouncing off hardware limits if you don't do the DSP thing.

And no - I'm not aware of any tube based DSP solutions, so I guess this is more of a SS vote, even though it's not. All the hardware used to get the DSP eq done is solid state though ...

Judges?

no, this is a general question. I will still built an EQ based on the old Blonder-Tongue, but probably in stereo.
Do I really need it?, no, the sound coming out of my system, to my ears, is pretty darn perfect.
So why bother?....cause I can and its a good learning curve AND its fun. I like tinkering  
The reason for this question is space, that is space in the chassis. I can squeeze it into the chassis I am thinking of using, it would be easier to build a mono in each chassis, but of course the cost would be higher.
Yes, I know how technical sound analysis etc can get, but lets face it, this is a hobby, for me anyway, and like I said above, its fun tinkering.
Thank you for all the input and ideas, much appreciated!

I have been considering building and offering for sale a hybrid tube EQ and/or crossover.   To do either right, with all tubes, would require DOZENS of tubes,
but if combining tubes and audiophile quality discrete op-amps such as those used in $500-2000 audiophile gear, it's not such a huge task,
can be done with maybe 4-8 tubes total.   So I'll add to the question, is anyone interested in either EQ or crossover using tubes?

Paul, this would be similar to the XM9 but using a mix of tubes and op-amps.

MontanaWay wrote:no, this is a general question. I will still built an EQ based on the old Blonder-Tongue, but probably in stereo.
Do I really need it?, no, the sound coming out of my system, to my ears, is pretty darn perfect.
So why bother?....cause I can and its a good learning curve AND its fun. I like tinkering  
The reason for this question is space, that is space in the chassis. I can squeeze it into the chassis I am thinking of using, it would be easier to build a mono in each chassis, but of course the cost would be higher.
Yes, I know how technical sound analysis etc can get, but lets face it, this is a hobby, for me anyway, and like I said above, its fun tinkering.
Thank you for all the input and ideas, much appreciated!

Ahhhhhh, space, the final frontier. I spent a delightful afternoon last Fall on the phone with a guy in California who builds million-dollar stereo listening rooms (we were arguing over whether tubes trumped s/s or not, voltage regulation, and such).
He said more can be accomplished with speaker and/or listening chair placement than any electronic tweak in the >$100,000 investment in electronics. And he was right; I was always wondering why the bass was better on my right channel than my left. Well, my RH speak is up against a corner wall; the left is up against am open wall. I walked that RH speak out of the corner a little bit, less than a foot, and Voila! no more imbalance. The room is everything.
I'd hate to see you put an EQ into the signal path, that's all. Any EQ induces distortion -- which is of course the point -- but it also invites other issues like RF and AC noise into the equation.
I'd crack open a decent bottle and bribe a friend over to the crib to move your speaks around while you sit in your favorite place. You would be amazed at what a foot or two, and some toeing in and out can do. And except for the price of the Scotch, it's a cheap fix.
Just IMHO. Sometimes, when it's as good as it gets,that's as good as it gets. So go blow a kilobuck on an Ortofon cartridge and spend some time on the turntable alignment. They DO make a difference.
My uber-rich California guy also said voltage fluctuations should not be an obsession; our tubes can handle a 10 percent swing and that's well within the 6.3-7 volt tolerance of our filaments. Bias your tubes at night when line demand is low and volts are high coming out of the wall, and you'll never cook 'em.

deepee99 wrote:

MontanaWay wrote:no, this is a general question. I will still built an EQ based on the old Blonder-Tongue, but probably in stereo.
Do I really need it?, no, the sound coming out of my system, to my ears, is pretty darn perfect.
So why bother?....cause I can and its a good learning curve AND its fun. I like tinkering  
The reason for this question is space, that is space in the chassis. I can squeeze it into the chassis I am thinking of using, it would be easier to build a mono in each chassis, but of course the cost would be higher.
Yes, I know how technical sound analysis etc can get, but lets face it, this is a hobby, for me anyway, and like I said above, its fun tinkering.
Thank you for all the input and ideas, much appreciated!

Ahhhhhh, space, the final frontier. I spent a delightful afternoon last Fall on the phone with a guy in California who builds million-dollar stereo listening rooms (we were arguing over whether tubes trumped s/s or not, voltage regulation, and such).
He said more can be accomplished with speaker and/or listening chair placement than any electronic tweak in the >$100,000 investment in electronics.  And he was right; I was always wondering why the bass was better on my right channel than my left. Well, my RH speak is up against a corner wall; the left is up against am open wall. I walked that RH speak out of the corner a little bit, less than a foot, and Voila! no more imbalance. The room is everything.
I'd hate to see you put an EQ into the signal path, that's all. Any EQ induces distortion -- which is of course the point -- but it also invites other issues like RF and AC noise into the equation.
I'd crack open a decent bottle and bribe a friend over to the crib to move your speaks around while you sit in your favorite place. You would be amazed at what a foot or two, and some toeing in and out can do. And except for the price of the Scotch, it's a cheap fix.
Just IMHO. Sometimes, when it's as good as it gets,that's as good as it gets. So go blow a kilobuck on an Ortofon cartridge and spend some time on the turntable alignment. They DO make a difference.
My uber-rich California guy also said voltage fluctuations should not be an obsession; our tubes can handle a 10 percent swing and that's well within the 6.3-7 volt tolerance of our filaments. Bias your tubes at night when line demand is low and volts are high coming out of the wall, and you'll never cook 'em.

I get where you're coming from.
Like I said, do I REALLY need an EQ?....of course not! Our living space is all open, and I mean all open. Kitchen, dining, living, one long room, ceiling goes from 10' to 18', no obstructions, except for the furniture. So walls etc are no issue with us, and the sound is awesome!
But I like to tinker, I like gadgets, I like to build anything tube, yes its an obsession...you got a problem with that?????  ......hehehehehe....so I'll build me one. It will have 11 tubes, 4 each for each channel, each channel will have 9 octaves, 2 tubes for the output amp and one rectifier. One transformer, one multicap and a lot of them itty bitty little leggy thingies with pretty color bands on them! Oh and some caps as well. The slide pots even have LED's on them...looks pretty cool!!!   
Hell if makes no huge difference and/or I get sick of it, I can always salvage 100% of the parts and use them in other tube gadgets. I already have most of the parts, so its no biggie!

tubes4hifi wrote:I have been considering building and offering for sale a hybrid tube EQ and/or crossover.   To do either right, with all tubes, would require DOZENS of tubes,
but if combining tubes and audiophile quality discrete op-amps such as those used in $500-2000 audiophile gear, it's not such a huge task,
can be done with maybe 4-8 tubes total.   So I'll add to the question, is anyone interested in either EQ or crossover using tubes?

Paul, this would be similar to the XM9 but using a mix of tubes and op-amps.

yup, I am...you betcha, put me down....gimme more gagdets....gadgets gadgets gadgets!!......  

MontanaWay wrote:

tubes4hifi wrote:I have been considering building and offering for sale a hybrid tube EQ and/or crossover.   To do either right, with all tubes, would require DOZENS of tubes,
but if combining tubes and audiophile quality discrete op-amps such as those used in $500-2000 audiophile gear, it's not such a huge task,
can be done with maybe 4-8 tubes total.   So I'll add to the question, is anyone interested in either EQ or crossover using tubes?

Paul, this would be similar to the XM9 but using a mix of tubes and op-amps.

yup, I am...you betcha, put me down....gimme more gagdets....gadgets gadgets gadgets!!......  

My light bill has gone up $20 a month since embarking on this obsession, and it wasn't cuz the rates went up or it was particularly cold.
I guess using GZ-33s aren't the best way to heat the house....

One place where EQ can add big value with minimal audible distortion is in the subwoofer frequency range. Parametric eq built into many subs is useful for taming room modes. The ringing of standing waves at those mode frequencies has a detrimental effect on our ability to hear other frequencies.

Yet the downsides of adding equalization, cross-overs, etc are minimized by the insensitivity of our hearing in those frequency ranges--we wont hear cross over distortion etc in the low registers the way we do in the vocal range where our hearing is very sensitive.

So in answer to your question, mono. I have two mono parametrics, one built into each of my 2 Rythmik subwoofers. One is taming a room mode at 70Hz, the other at 46Hz.

Tube Nube wrote:One place where EQ can add big value with minimal audible distortion is in the subwoofer frequency range. Parametric eq built into many subs is useful for taming room modes. The ringing of standing waves at those mode frequencies has a detrimental effect on our ability to hear other frequencies.

Yet the downsides of adding equalization, cross-overs, etc are minimized by the insensitivity of our hearing in those frequency ranges--we wont hear cross over distortion etc in the low registers the way we do in the vocal range where our hearing is very sensitive.

So in answer to your question, mono. I have two mono parametrics, one built into each of my 2 Rythmik subwoofers. One is taming a room mode at 70Hz, the other at 46Hz.

I would still recommend having a friend over to move the speaks around a little bit, esp. the sub-woofs. You'd be amazed how a few inches can accomplish what thousands of bucks can do.

I think thats great advice.

I was inspired by this thread to experiment with my speaker placement, left channel always seemed distant or lacking and sure enough after a little trial and error moving it out from corner 6" made a huge improvement!
Just put some KT-120s in my ST-120 and enjoying!
thanks for sharing

Don't forget your toes!

sKiZo wrote:Don't forget your toes!

That's also good advice, especially if your speakers are heavy.    Messing with the toe-in (actually in my case toe-out made a very nice improvement to the sound stage; just aired everything out.

I can see a potential use for a mono tube EQ for evaluating speakers. Many of the cabinet and baffle designs I build are unconventional and it would be good to have a simple way to vary the signal to the drivers. I have looked at MiniDSP, but can't quite commit to adding it into the circuit. I've also thought about building a board with various coils and capacitors so I might easily vary the passive crossover frequencies to the midrange and bass drivers, I already have a similar board I use for the tweeters. In that I sometimes mill one baffle and build one cabinet initially, mono would be adequate.

What would be best for me would be an EQ with multiple outputs so I could split and adjust the output signal to separate amps if I chose, or, use a single adjusted output to a single amp.

I think that an equalizer is for use in a monaural amplifier, only for discs 78 rpm and Mono vinyl for the first time.
To do this I use a monophonic amplifier Bell 2200B, which already has six positions for phono equalization.