EQUIPMENT REVIEWS

REVIEWS OF NEW ITEMS

1: DACT ultra high end attenuators and switches (and now, PHONO and LINE AMP MODULES!!)

DACT ATTENUATORS and SWITCHES (and now, PHONO and LINE AMP MODULES)

i approached DACT to try some of thier attenuators, and switches, always wanting to be at the cutting edge of new technology. they sent me some SAMPLES, enough to do my entire signal path for a very good test..this being my preamp /headphone amp unit that is the hub of my studio. Over the years, i have used pretty much all the commercial pots, and tended to be set in my choices, for various price points..i use ALPS for the mid grade stuff, and either ALPS or Bournes conductive plastic for my upper end gear..sometimes, i made my own ladders, using various high end switches, and individual resistors. To be honest, when i found out the PRICE of the DACT units, i was a bit sceptical..you see, the idea with these things is that surface mount resistors have shorter leads, and no inductance to speak of. HONESTLY, i found it hard to swallow that i could hear the differance on a 100k fixed resistor, from one type to another, no matter how much you shortened the leads to the resistor body.
I resisted actually TRYING the samples they sent me, until one day my tube unit packed it in, needing a new power transformer..yes, folks, i actually didnt put a fuse in it. YOU KNOW WHAT THEY SAY about a tradesman and his own equipment...i use a totally redone PAS preamp, and the original units never had fuses..i simply forgot, on my own unit, to put one in. I digress, however. IN the preamp, it has the highest end circuit design, components. srpp 5751 black plate tubes, teflon boARDS, silver and teflon wire, rifa and solen caps, the works. THis preamp is the best design i have heard, in literally hundreds of designs over the years..
I have built em all, from hoover dam power supply giant rack regulators, which would run the darn thing for 5 minutes, unplugged!! to things like the CURCIO "daniel"types, chock full of nasty solid state regulators ...i have tried most circuit topologies as well, having made over100 modified PAS preamps alone, over the years..the PAS power supply is dirt simple, and effective. I use exclusively BLACK PLATE tubes..the guys with the shiny black plates, generally military surplus..they have almost IMMEASURABLE 4th and 6th harmonic distortion, and much better bottom end than gray plate equivelents..they actually sound more ACCURATE.. But i have found that they "voice"best with simple supplies..if you over regulate them , they start to sound like TRANSISTORS..
SO,with black plate tubes, i personally DONT like solid state regulated power supplies, preferring instead simple tube rectified b+ with lots of fast caps. I also like the 24v series connected heaters, but thats a whole 'nother article.
Back to the DACT gear: i went ahead and changed the selector switch ( a very high end unit, which allows you to switch the grounds, as well as the hot terminals, a feature i like a lot) and two pots i was using ( i use a PRE gain stage and POST gain stage pot...in my preamps, i prefer to control volume AFTER the active stage..this gives you better signal to noise, than simply having a pot BEFORE the stage..but i put a pot before the stage as well, as my heaphone output comes after the tube stage, but before the output pot. this gives me independant headphone and amplifier volume controls, centrally located.
I was using ALPS black beauty conductive plastic pots, and changed to the DACT stepped 100k upper end units. I wasnt prepared for what i heard. there was a HUGE differance in clarity, and i had to swallow my expectations.
these are the best controls i have ever heard, period. they are obviously more expensive than a conductive plastic pot..4 times more expensive, actually. But when you are building state of the art equipent, and in my case the two controls are the ONLY resistors in series in the signal path at ALL, you can really hear the differance in the resistive component.
i will use these units on everything where i value the signal fidelity. PERIOD.
THis gets expensive in a recording studio, but in mine, i tend to do all my mixing digitally anyway, i dont go for analog control surfaces, or digital models of analog control surfaces.. i think they are obsolete, in a day where you can draw all your fades directly on the waveform. i see NO need to have motorized faders..and compound the reliability problems of digital WITH the reliability problems of analog...SO, really, i dont have too many places where i use pots. DACT makes specialized controls for any level you might require, anyway..including multiple deck units for 5.1 surround, etc..to be honest..this is a new state of the art. Sad to say, you CANT actually make them yourself, in this case..SMT components require automated soldering, so you will have to dig deep and simply purchase them.
to my AUDIOPHILE FRIENDS, i urge you to GET RIGHT ON IT, if you can afford it,
and make your controls DACT/. you will NEVER look back..there is simply NO contest.

i will be reviewing thier active preamp units, as both a preamp and a headphone amp, in the next little while..i see other possibilities for these circuits..while they wont be the same FLAVOUR as my all tube unit, i see applications for them as ultra high end DI boxes..and state of the art interfaces for those nasty piezo guitar pickups which need to see a much higher impedance than most devices are capable of.
DACT also makes an ultra high end PHONO preamp..i think that you DJ types can afford to upgrade your preamps and mix electronics, to an audiophile level. i cant BELIEVE the crap that those nasty dj consoles are made with..come on your guys..ever hear an audiophile PHONO system?
the DACT stuff has the best noise specs of any phono preamp on EARTH, period.
should be interesting to try.. GO TO THE DACT web site

DACT PHONO and LINE AMP MODULES:

With the incredible success of the stepped smt attenuators, I just HAD to try the preamp modules.

DACT makes two units, a stereo phono preamp, and a stereo line amp.

These make use of the same ultra high end components and methods as the attenuators, and have absurdly great technical specifications.

Specs alone don’t always make a unit musical, as we all know, so here is my thoughts from my tests..

I will basically cut and paste from my email to the head of DACT.

The email excerpted as follows:

***************************************************

ok...here goes.

I tried the ct101 today, as a headphone amp.

( I tried it as a line amp in my stereo also)

It sure benefits from warm-up period..i would suggest telling people to burn

it in for at least 20 minutes before listening for the first time

( maybe you already do this)

I am using mine into a pair of senhiesser 580 phones, rewired with silver/Teflon.

a modded Denon is driving it. solid silver interconnect.

I used your attenuator, and twin power one regulated supplies.

SUBJECTIVELY, its ALMOST as good as my tube unit. almost.

the clarity is so close, its hard to choose between them..at times I gave

the edge to either...but, there is something with the tube one that is subjectively different,

and it WONT go away. A kind of listening fatigue missing with the tube unit.

you can listen to it for HOURS..it sounds like real life, or rather is

quite euphoric to listen to..

tickles your brain in a different way...

I went back and forth several times, to be sure..used lots of test material.

I also noticed large differences in sound quality at the different gain

levels..0 was by far my preference, though 6db was pretty good as well, you

could clearly hear the drop in fidelity between 12 and 6db

*******************end of email quote*****************************

I CAN , even though I like my own tube preamp design better, see purposes for this unit.

First, when I was making my tube unit commercially, I charged about $800 US for it. It would be MORE than that today.

DACTs is significantly less expensive. Because of the BATTERY power potential,

It opens up the world of remote recording …a good headphone amp when recording in the

Field is a great thing. I have listened to lots of solid state preamps..this one sounds as smooth as the best jfet

Class a units, and has lots of detail..without sounding HI FI..this is hard to do with solid state preamps, especially using

Bipolar transistors. It would be a great match for tube amps with extra plush sound.. LEAK, for example.

Though it goes against what I would in theory believe to be the best case..i like the sound of an active preamp better than

A passive one, I am afraid..this probably because the type of circuit and power supplies for a good preamp usually has

A bit more overbuild than a generic front end for an amplifier. In my experiences, lots of amp stages don’t supply linear amplification

At all gain levels..they tend to compress as they run out of headroom….and many AMP designs use global feedback around several stages,

Introducing time based problems that aren’t always as obvious with local feedback, or no feedback at all.

Sometimes, instead of COMPRESSION, a good preamp circuit can help to RESTORE the dynamics lost in the compression of other parts of the

Signal path…when you listen to my tube preamp plugged into the insert of a recording console, you get a sense of LIFE, more dynamics..the source material you are listening to sounds more like it actually DOES..( obviously its better yet, when my preamp stage REPLACES other gain circuits, but when you choose to have it in the signal path when it is actually REDUNDANT GAIN, it must be doing something that you like

Subjectively. The DACT seems to do this as well..it has an easy dynamic that I like…lots of seperation, soundstage no problem.

The price is right also.

I will be testing it as an active amplifier for piezo type guitar pickups..those like the super high impedance that this circuit will present..

It should be an amazing application for this preamp. I am hoping I can derive a balanced signal from it, on the output as well.

-*******************return to email quote***********************

*****************time passes****************************

ok...tried it as a main stereo preamp.

my preamp gets a boost, from the headphone test, in this case, as I am no

longer going through the transformer...( the dact is no longer using the

resistors, or output cap so gets a boost also.)

seems the tube one wins again...in terms of palpability, realism.

I am NOT invested in the outcome, please understand.

I want BETTER, in any circumstance, period.

my tube equipment is not at all like things on the open market, for the

most part..

I use old stock black plate tubes, which are hard to come by, and very

simple power supply, in very simple circuits..

my amps are in some of the top studios in the world, though I no longer

make them commercially.

subjectively, I LIKE your preamp, as a preamp, more than ANY solid state

preamp I have heard. Its VERY clear, but NOT hard or artificial sounding, as

many ( even PURE FET, CLASS A ) preamps have sounded to me.

but, I do get a bit of veiling, a smaller sound stage, and slightly less

palpably real sound.

if I didn’t have both to compare, I would no doubt be VERY pleased with your

unit, as my stereo.

it might mate well with SE triode amps, something with exaggerated

plushness...

once again, even though I MADE mine, I honestly would have been happily

pleased to replaced them with yours...I would have proffered the lack of

periodic re-tubing, simplicity of power supply, etc.

lets see how the turntable fares.

*****************MORE TIME PASSES, hours, in fact************************

OK, you got me.

the turntable is INCREDABLE.

HANDS DOWN smokes my own tube preamp.

its SO nice to have the kind of clarity like this, without the noise, which

I cant seem to totally remove from the tube setup.

WOW.

its quite amazing, easily showing differences that weren’t being resolved by

mine.

an album I used to use, to show off my system, clearly had faults, so much,

in fact, I cant listen to it, without hearing them. ( no, I don’t care, as

some others got SO MUCH BETTER it was astounding...)

got to compare cd and album directly, on some where I have both, the album

is right there, now, in terms of dynamics, noise, etc.

I am running your pre into my tube line stage though, it likes this...

man, I am happy with this.

*even more time passes************************

***********he digs out his records**************

*********************this*********************

*******************************is************

*************************************the*****

*******************fun part*******************

MILLENNIA MEDIA 990 PREAMP MODULE

I approached John La Grou at Millennia Media about trying out the new 990
compatable CLASS A j-FET op amp after reading about it's release..He was easy to deal with ,
no doubt quite comfortable in the knowledge that MM makes the industry standard mic preamp ,
the HV-3, used by a rediculously long list of recording industry big wigs...( go to the site and see for
yourself..... be prepared to wish YOUR client list included this array of experienced ears)
anyway..while I was pondering which circuit to use the test pair on, a fellow sent me his prototype API 520 based pcboards... and I figured I would use those, but with MY personal favorite NEW transformer design, the LUNDAHL amourphous strip core. ( almost DC -150k flat ....)

I also used a ladder gain control, so only ONE resistor was in the feedback ( gain control) path.
I needed a dedicated mic pre with enough gain for a pair of low output multipattern ribbons I recently aquired...copies of RCA 77dx, with - 77db gain specs, if you can believe that.
The reason I probably GOT them at all, was that most vintage tube and stock console preamps
JUST cant do the gain needed, especially if you want to add a bit of compression...
anyway..I fired up the preamps, suprise, no smoke, and the things sound AMAZING.
WARMER than my referance custom GREAT RIVER preamps..but very similar.
It now sounds like the MICS are the weakest link.....
Once you get up into the best preamps and transformers , there isnt as much differance in sound
as you would get from lesser units.
I suspect the extra warmth is the JENSEN output transformer I used on this unit..definately the weak link
in the signal path....I am going to put an unbalanced out on the pre, so I will see where it goes,
and add to the review at that time....
I WAS able to put the gain up to almost wide open with NO noticable noise at all....
I suspect this unit will surpass the Great River by a tiny bit, in the lushness department..as it is ALL Jfet
BOTH ARE EXCEPTIONALLY QUIET UNITS.
I would reccomend these op amps without hesitation, if you are thinking of making
990 / 2520 based circuits...I cant wait to try a transformerless design using another quad of them
I am also going to use this unit as gain recovery for my home built PULTEC eqp1a's...
I have application sheets for LOTS of circuits using 990 and 2520 units...

Dont get me wrong...I love TUBES still...but I have been tending towards RIBBON mics,
and CLEARER , QUIETER electronics lately....less noise...
Cant really find ANYTHING imperfect about these units.....
if I was building a CONSOLE, I would use these in a heartbeat..
for the field servicability factor and the state of the art sound quality.
GO TO THE MILLENNIA WEB SITE

NEW INEXPENSIVE SHOCK MOUNTS FOR ANY MIC!

I saw these on EBAY, and sent for a pair..
here is a picture of one holding an EV re20..a pretty hefty mic..
they arrived PRONTO, in great shape, and included a little stick even, mounted in one,
as an example of how to mount a smaller mic...differant than a larger one, which just pushes in.

These work GREAT, in terms of grabbing the mic..much more solid shock elastic than that found
in MUCH more expensive units..i have seen an old unit that used a similar principal, but
sadly, it used cheezy hair elastics..which couldnt work for larger mics, and really werent up to the
task...i feel CONFIDENT in these units..not worried the elastic will break , like on the ones that
originally came with my RODE nt2's way back when before they beefed thier elastic.

these are a BARGAIN, the only beef i have, as with pretty much ALL mic shock mounts, is the
tensioning unit for the SWIVEL part of the unit is SCREWDRIVER driven..this is nice and SOLID though..
.but you need a tool, where a big nut , or wing nut might be even better.
this is VERY MINOR, as the units come preset with just about the right amount of tension for any mic i tried.
i like and recommend them..

GO TO THE SHOCKMOUNT WEB SITE

MONSOON FLAT PANEL SPEAKERS

i got a couple of sets of these, being interested after hearing them hooked up to a PC in a computer store. i DIDNT get the amp, or subwoofer unit, so cant comment on those.. I have a recording studio, and was looking for some nearfields that DIDNT suck, in an ultimate sense. ( sorry, as indicitive of bad 1960's TV sound as auratones are, i dont actually want to spend MY time on this earth listening to them. ALSO, lets face it, time moves on..i am not going to sacrifice the STEREO field on my recordings for mono compatability, either..sorry..you have to decide at some point WHO your audience IS, actually, and raise the bar. After YEARS of making audiophile equipment, i just dont mix for bad equipment, period. SO, that said, i was going to make myself a single ended small tube amp to drive the monsoons..but first, i wanted to check the frequency range of them..the crossover point they specify is quite high, and i have found that often, the tradeoff of volume, versus bass has me wanting to get more response from the ligher element, at the espense of the ultimate volume the system is capable of. in this case, if i want LOUD, i will use my monster house system..all of 80w per channel of TUBE mono blocks...(
For curiousity, i first decided to try the monsoon with my mono amps, at low volume , full range.. and i have to say, i was suprized by a sibilance in them in the top end..a tizzyness, that i dont like in lots of audiophile systems, that sound like expensive stereo equipment, rather than the natural source material. dissapointed, i ended up thinking, ok, when i build the tube amp, i will tailor the top end to suit the speakers.. THEN, i though, ok, till then, i hook em up to the SOUNDBLASTER card i use for gaming, and a nice little stereo sub unit i have for the purpose..an advent mini sub..i love that little sub..it sounds great, and works differant than other units..instead of summing to mono, and having a crappy crossover, they use TWO hefty drivers, in a band pass cabinet, in TRUE stereo, internal in the box. no coils, no summing, no crap.
works GREAT in practice..i was suprized. i decided i liked the FULL range sound of the monsoon, despite warnings of bass killing them from the manufacturer, so i wired em in parallel to the sub. The results are great, with a bit of tweaking of the sounblaster tone controls...actually quite great..equal to the bose labrynth stuff, as nearfields..wouldnt change a thing. The setup is satisfying enough to negate the need for a new amp. Images like crazy, much more than regular speakers in the PC size range..it has huge soundstage, and none of the tizzy top end..maybe my amp overwhelmed it, maybe its a damping issue, no idea.
i LOVE the monsoons, they are great value..as a pc speaker, for which they were no doubt actually VOICED, they are ideal. i referance all my mixes through them, my tube headphone/senhiesser580 (rewired with ex cray supercomputer silver and teflon lead wire) and my big setup, which is the tube pre from the headphone amp, my own mono tube amps, kef concentrics in composite ROUND enclosures, with hiel air motion transformers for the top end. i am still working on the bottom end of my big system..i think i will go with biamped mos fet bottom end.. My system for biamping is to leave the full range amps running full range into the main speakers, PERHAPS putting in a 6db rolloff in the lows by simply shrinking ONE cap at the input of the amp..then use ACTIVE class A discrete electronics, with a frequency adjustable BELL eq driving a good amp and seperate speakers, purpose built for the low end. still have to MAKE those speaker cabs. i might go with more ROUND composite cabs..not sure. cheers.