Need Preamp/Amp Recommendation for Passive Speakers

[chipwits]

Hi,

I've decided to go with Truth Audio TA-P1 passive speakers and I was wondering if anyone could recommend an affordable "quality" preamp and amp for it. Affordable quality examples: My Lynx Aurora 8 versus Apogee 16A/D (50% savings); DIY Seventh Circle Audio preamps (50% savings per channel).

So looking for a preamp / amp that is a fraction of the cost of the "top of the line" units but 99% as good.

Help me please hehe.. I am clueless.. new area for me. Maybe I should pick up some cheap adcom preamp/amps from the paper.. lol.

James

[xstatic]

Preamps are for mics, and in this situation amps are for speakers. Hafler makes good affordable amps, or look for a used Bryston or Parasound amp In your previous thread you wondered about balanced connections on the Truth Audio monitors. There are no connections except for speaker connections. The balanced connection would go to your amplifier.

[BigRay]

hafler

grab one off ebay.

i use hafler for m\y truths and bryston for my B+Ws.

[chipwits]

Originally Posted by xstatic

Preamps are for mics, and in this situation amps are for speakers. Hafler makes good affordable amps, or look for a used Bryston or Parasound amp In your previous thread you wondered about balanced connections on the Truth Audio monitors. There are no connections except for speaker connections. The balanced connection would go to your amplifier.

Ahh I see. I guess I misunderstood because when I was looking at home stereo units about 10 years ago the sales person was recommending I went with a "separates" system where the "preamp" and the amplifier were two different units. I just read the following from Wikipedia on preamps:

.. "In a home audio system, the term 'preamplifier' may sometimes be used to describe equipment which merely switches between different line level sources and applies a volume control (attenuation), so that no actual amplification may be involved." ..

I was under the false impression that a home stereo "preamp" took a line level signal and amplified it a bit to a level the connected amplifier would be satisfied with.

So I guess I need that Presonus Control Center afterall since it has a volume control knob. If I take the output of the Lynx Aurora 8 D/A converter and plugged it directly into the amp, the amp would blast the signal out with its full wattage, busting my speakers in the process.. right?

I guess I just thought a "preamp" was required for a "separates" home stereo system as an extra stage of amplication as well as some volume control in that middle stage.

Perhaps someone can clear this up for me. Hehe. Thanks.

Btw, thanks for the Hafler recommendation. Any particular model I should get?

Also, regarding the balanced inputs on speakers... I "swear" I've seen speakers with balanced inputs. And I was even told by a friend a few years back that I should look into balanced input speakers. But perhaps this doesn't affect the sound much. Dunno.

James

[pohaku]

You can also use an A-Designs ATTY or an NHTPro PVC which are passive volume controls to control volume to your monitors. They run about $100 new. I have powered monitors (NHT A-10s and an NHT sub) and I use the PVC.

[BigRay]

Originally Posted by chipwits

Btw, thanks for the Hafler recommendation. Any particular model I should get?

I use the hafler pro 1200..but..
http://cgi.ebay.com/VINTAGE-HAFLER-D...QQcmdZViewItem

[chipwits]

So for example, I'd just take the output of say a Mackie Big Knob, Presonus Control Center, A-Designs ATTY or NHTPro PVC and plug that directly into the amp (e.g. Hafler Pro 1200)? Didn't realize a line level signal gets its volume lowered before going into an amp; thought it was a very low signal that gets boosted up somewhat before going into an amp.

james

[gecko zzed]

Originally Posted by chipwits

Also, regarding the balanced inputs on speakers... I "swear" I've seen speakers with balanced inputs. And I was even told by a friend a few years back that I should look into balanced input speakers. But perhaps this doesn't affect the sound much. Dunno.

James

I am sure you have seen speakers with balanced inputs, but I reckon they will have been active speakers (i.e. within the case they have their own inbuilt power amps).

Getting powered monitors is not a bad option and worth looking at.

[chipwits]

Thanks. I am gonna go with a Hafler amp and Truth Audio TA-P1 set of passive speakers I think.

Thinking about making my own DIY control center using a high quality stepped attenator and some switches for inputs and outputs. I wanna make something as passive as possible and have read that "stepped attenuators" are the cleanest. If anyone can recommend a "stepped attenuator" part that would be great! I've only seen one so far in this new area of research for me:

http://www.penguinlovers.net/audio/Attenuator.html

I want build something as passive and clean as possible that will rival $1000-$2000 solutions, but costs me under $200 in parts =P. All I need it for is attenuating volume.. we are just talking resisters here heh. I will use a Rane HC6 for headphone amplifier etc.

James

[chipwits]

And another supposedly super high quality Volume Attenuator for DIY:

http://www.goldpt.com/prices.html

[SRR]

http://cgi.ebay.com/PRESONUS-Central...QQcmdZViewItem

http://cgi.ebay.com/PreSonus-Central...QQcmdZViewItem

I am all for DIY when it gives you something better, I don't see a $200 volume control as better, or even in the same league as the central station, the routing, the digital inputs, the metering, ETC. If the central station is to much there is always the mackie big knob, and if that is to much samson has one for $100, and if that is to much behringer has one for $33. I couldn't tell the difference between a passive SWITCH (not volume control) and the $33 behringer, so guess what I have. It has four stereo inputs, 3 stereo line level outs for speakers, talk back mic, talk back foot switch input etc. I am pretty sure you will find all that and more in the mackie and presonus units. You may not need all these features now, but what about next year as your studio grows? Or the year after that, your $200 volume control will be sitting on the shelf, atleast that is how I see it, IMHO, YMWV, etc!!!

[pellgarlic]

Originally Posted by SRR

behringer has one for $33. I couldn't tell the difference between a passive SWITCH (not volume control) and the $33 behringer, so guess what I have. It has four stereo inputs, 3 stereo line level outs for speakers, talk back mic, talk back foot switch input etc.

sorry to butt in here, but i just wanted to ask a quick question, as i'm looking for a similar solution to the original poster - i've already got a pair of speakers, and am currently using a hi-fi separate amplifier (it's a denon - never heard of them before i got it second-hand from a friend). it's not bad for what it is - has a "direct-source" button and the sound quality is acceptable, but the headphone socket doesn't work, and is unfixable. i'd like a fairly basic, cheap, but decent quality amp, nothing too fancy or complicated, just an amp with a volume and some tone controls (whether just bass and treble, or something more). the behringer and samson you mentioned sound interesting, but i can't find anything (using google) that might be them - can you tell me what the models you are referring to are?

cheers.

[c7sus]

I picked up a really clean used Carver PM-120 for about $150 at GC last year.

I guess they go for about $100 on Ebay when the come around.

[Kevin Deschwazi]

Stepped attenuators here:

http://www.triodeelectronics.com/4pol24posals.html

http://www.dact.com/html/attenuators.html

http://www.goldpt.com/

A similar project to what you're considering here (with some good critique, schematic, troubleshooting and theory):

http://www.prodigy-pro.com/forum/vie...hlight=stepped

[chipwits]

Thanks Kevin. Here's another really interesting one (fairly new):
http://jos.vaneijndhoven.net/switchr
http://jos.vaneijndhoven.net/switchr/design.html

[chipwits]

Yeah I am definitely going to build a stepped attenuator. So much better than any pot. Pots have bad stereo tracking (10%-20% tolerance) whereas with stepped, using resisters, .05db tolerance.

James

[Minion]

You can Probably make your own Custom stepped attenuators useing some rotary switches (Lorins??) and some 1% metal film resistors...

I use them as Gain controlls for some of the DIY preamps I build in 6db steps....

Just a thought....

Cheers

[Kevin Deschwazi]

Originally Posted by Minion

You can Probably make your own Custom stepped attenuators useing some rotary switches (Lorins??) and some 1% metal film resistors...

I use them as Gain controlls for some of the DIY preamps I build in 6db steps....

Just a thought....

Cheers

Yeah I was gonna mention that but they're fiddly as hell and i hate doing them myself so i didn't bother.

[notCardio]

Originally Posted by c7sus

I picked up a really clean used Carver PM-120 for about $150 at GC last year.

I guess they go for about $100 on Ebay when the come around.

GC has Carvers????

I haven't been there in a litle while, but I sure as hell never saw them there!

And pellgarlic, the Denon should be a damn fine amp. What's the power rating on it? I might be interested.

[SRR]

Originally Posted by pellgarlic

sorry to butt in here, but i just wanted to ask a quick question, as i'm looking for a similar solution to the original poster - i've already got a pair of speakers, and am currently using a hi-fi separate amplifier (it's a denon - never heard of them before i got it second-hand from a friend). it's not bad for what it is - has a "direct-source" button and the sound quality is acceptable, but the headphone socket doesn't work, and is unfixable. i'd like a fairly basic, cheap, but decent quality amp, nothing too fancy or complicated, just an amp with a volume and some tone controls (whether just bass and treble, or something more). the behringer and samson you mentioned sound interesting, but i can't find anything (using google) that might be them - can you tell me what the models you are referring to are?

cheers.

This is the one I have, its was $33 from fullcompass, call them up they should give that price:

http://www.musiciansfriend.com/produ...xer?sku=182041

This is the one berry ripped the design from:

http://www.sweetwater.com/store/clos...-img_front.jpg

And these are just line level devices, you will still need an amp, and no bass/treble controls, if your monitors are somewhat flat, you shouldn't need bass/treble controls.

[chipwits]

Kevin (or anyone else that knows),

I notice many amplifiers also have balanced inputs. My question is, is it really needed?

Microphones to preamps definitely need balanced since it is a very low voltage , low impediance signal traveling potentially over many feet. I understand the purpose here. However, the output of my D/A converter to Volume Attenuator to amplifier is only about 3 or 4 feet. Also the signal is at line level by this time, and much higher impedance.

Would I hear any difference whatsoever if I only ran 2 feet of unbalanced cable from my Volume Attenuator to my amp? I also wonder what many of the amplifiers *really* do inside with the balanced signal, if they do the correct differential amplification etc with it, or just really only uses the non-inverterted signal of the two.

The reason I ask this is, I want to save on cost of parts in my DIY volume attenuator. For balanced, I'd need twice as many resistors and relays.

James

[pellgarlic]

Originally Posted by notCardio

pellgarlic, the Denon should be a damn fine amp. What's the power rating on it? I might be interested.

actually, sorry to disappoint you, but i've started another thread here: http://homerecording.com/bbs/showthr...29#post2236929 where i've become convinced to keep the denon amp, and am leaning towards spending my money on replacing my current sony hi-fi speakers with proper monitors instead i just need to either get the headphone socket fixed, or else hook up something that will allow me to switch the audio coming from my computer to go between the denon amp or a separate headphone amp. anyway, don't want to monopolise this thread - got my own going now...

thanks for the response SRR, but as i say, i think i'm gonna spend my cash on monitors now, rather than a (seemingly un-needed) new amp. guess i've got a lot to learn

[Minion]

Originally Posted by chipwits

I also wonder what many of the amplifiers *really* do inside with the balanced signal, if they do the correct differential amplification etc with it, or just really only uses the non-inverterted signal of the two.

James

Most solid state Amps use a dual inverted output to create a Ballanced Signal (Non phaze inverted wouldn"t really be Ballanced, Or would it??) useing a Dual Opamp like the TL072 or NE5532...so to create a ballanced output you really don"t need many more Parts than an Unballanced output if useing an Opamp...You can create a Ballanced Line driver from 7 Resistors and One opamp and only take up a PCB space of about one Square inch useing a Circuit like this...


Cheers