What Preamp Should I Get?

[Aaron Bilger]

So I have been wanting to upgrade from my old 20 year old preamp it's got problems and I don't want to mess with it how much could I get for a new preamp around $500-$600 and I would love it to be a 5 or 7 channel surround sound kinda like the new AV receivers have nowadays but I got a new amp 2 months ago and don't need a receiver only a good preamp it has to be new so I can get the most time with it before any other problems happen in a few years I don't like having to use someone else's problem preamp.

 

[everettT]

Just get this refurbished av receiver and use it as a preamp only @$499 it's hard to beat
http://www.accessories4less.com/make-a-store/item/marsr6009/marantz-sr6009-7.2-ch-x-110-watts-networking-a/v-receiver/1.html

 

[Irvrobinson]

Outlaw 975:

https://outlawaudio.com/products/975.html

 

[Aaron Bilger]

Should I just save up $1000 and get me a good preamp? I have used a receiver as a preamp and they over heat from not using power.

 

[Irvrobinson]

Should I just save up $1000 and get me a good preamp? I have used a receiver as a preamp and they over heat from not using power.

There's something about the 975 that turned you off? You can get much better pre-pros than the 975, but $1000 isn't enough. As it happens, Music Direct has the Marantz AV 7702 on sale for $1200:

https://www.musicdirect.com/Store/marantz-av7702-112-channel-surround-preamp?utm_source=googlepepla&utm_medium=adwords&id=38117147883&gclid=CK7Irbzvks8CFVJbfgodCAMH0w

 

[Aaron Bilger]

That's not bad it's something like that I'm wanting to get. But would I have any issues with that preamp "Marantz AV 7702" since I use a Crown XLi 800 as my amplifier on my PC?

 

[Irvrobinson]

That's not bad it's something like that I'm wanting to get. But would I have any issues with that preamp "Marantz AV 7702" since I use a Crown XLi 800 as my amplifier on my PC?

I don't understand the question. The Crown is certainly compatible with the Marantz (or the Outlaw, for that matter. since the Crown has voltage gain of 29db). What do you think is the problem?

 

[everettT]

Should I just save up $1000 and get me a good preamp? I have used a receiver as a preamp and they over heat from not using power.

How do avrs over heat by not using power? But if you believe that and based on your budget, Irvs recommendation fits the bill.

 

[Aaron Bilger]

Well mine gets very hot on the top and I call that over heating because it is shortening the life the the receiver but I will get the preamp the Marantz I will get.

 

[slipperybidness]

Well mine gets very hot on the top and I call that over heating because it is shortening the life the the receiver but I will get the preamp the Marantz I will get.

Yeah.....Power (dissipation) is what causes heat!

Running the amps idle isn't causing it to over-heat! Now, if it is a Pure Class A topology, those tend to run hotter at idle than a class A/B or class D amp. If you want to learn about this, go read up on amp topologies, biasing, and quiescent current.

The general rule of thumb is to place your hand on it. If you MUST pull your hand away due to the heat, then it's too hot. If you can leave your hand on it indefinitely, then it's fine.

Now, you may have some issues going on causing excessive heat, but running (properly functioning) amps at idle won't do it.

 

[Irvrobinson]

The general rule of thumb is to place your hand on it. If you MUST pull your hand away due to the heat, then it's too hot. If you can leave your hand on it indefinitely, then it's fine.

Now, you may have some issues going on causing excessive heat, but running (properly functioning) amps at idle won't do it.

Hmmm... this isn't entirely correct. First of all, if there's enough heat in a chassis to make the top very warm to the touch, you're almost certainly reducing the service life of the unit's capacitors if you leave the amp powered on most of the time. Unless very high quality capacitors are used, 10-20 years is in the typical lifespan range, and a consistent environment of ~100F may shorten that range considerably. Large LCD displays, for example, which can get very warm due to dissipating a few hundred watts and the manufacturers' desire to offer very thin cabinets, often fail due to capacitor problems.

A very warm chassis, but not too hot to leave your hand on, is the sign of inadequate cooling, either in the chassis itself or due to the placement of the unit in some type of enclosure. It doesn't matter what operating class the circuits have.

 

[slipperybidness]

I guess i wasnt specific enough on my response for the OP. Good catch on that!

When I refer to the "hand test" for heat, I typically put my hand ON THE HEATSINK, not the chassis.

I tend to prefer amps that have the heat sinks external/integral to the chassis.

So, it made sense to me when I was writing it, but I see how that could be ambiguous now.

An IR thermometer is an even better approach here.

However, my other comment is accurate--running a properly functioning amp at idle should not cause excessive heat

 

[everettT]

IIRC the unit he is referring to is either a yamaha 995 or 2095 which would put the unit over 15 years old, and before the purchase of an external amp he was running A+B speakers at above average levels. If the gear would have been used properly, he would of gotten more years out of it. Those yamaha units were well built .

 

[DD66000]

Yeah.....Power (dissipation) is what causes heat!

Running the amps idle isn't causing it to over-heat! Now, if it is a Pure Class A topology, those tend to run hotter at idle than a class A/B or class D amp. If you want to learn about this, go read up on amp topologies, biasing, and quiescent current.

The general rule of thumb is to place your hand on it. If you MUST pull your hand away due to the heat, then it's too hot. If you can leave your hand on it indefinitely, then it's fine.

Now, you may have some issues going on causing excessive heat, but running (properly functioning) amps at idle won't do it.

Well, even class A amps don't necessarily run overly hot.
My Parasound A21 is almost running entirely class A....rarely will go to class A/B....and it's only barely warm after running two hours.
The AVR I was using would get quite hot, despite it was in a completely open rack, and near the floor, and plenty of space all around.

 

[Irvrobinson]

Well, even class A amps don't necessarily run overly hot.
My Parasound A21 is almost running entirely class A....rarely will go to class A/B....and it's only barely warm after running two hours.
The AVR I was using would get quite hot, despite it was in a completely open rack, and near the floor, and plenty of space all around.

You're incorrect on two counts. Your Parasound A21 is a Class AB amp. Parasound is just using audiophile double-talk with that Class A/AB designation. All Class AB amps work like that, it's just a matter of the standing voltage on the output transistor power rails, which is design-specific. If after two hours the amp is barely warm I would guess the Class A envelop is at most a few watts into 8 ohms.

Second, any true Class A amp runs very hot; annoyingly so. Class A amplifier power efficiency is pretty low, I'd guess 30% or so, so a true 100 watt/ch Class A stereo amplifier would dissipate something like 600 watts continuously at idle, which is almost exactly what I saw with the only true Class A amp I've ever owned, the Krell KMA-100 MkII mono block. If I used them for a few hours they would warm up my then modest-sized (~20x18) room.

 

[DD66000]

You're incorrect on two counts. Your Parasound A21 is a Class AB amp. Parasound is just using audiophile double-talk with that Class A/AB designation. All Class AB amps work like that, it's just a matter of the standing voltage on the output transistor power rails, which is design-specific. If after two hours the amp is barely warm I would guess the Class A envelop is at most a few watts into 8 ohms.

Second, any true Class A amp runs very hot; annoyingly so. Class A amplifier power efficiency is pretty low, I'd guess 30% or so, so a true 100 watt/ch Class stereo amplifier would dissipate something like 600 watts continuously at idle, which is almost exactly what I saw with the only true amp I've ever owned, the Krell KMA-100 MkII mono block. If I used them for a few hours they would warm up my then modest-sized (~20x18) room.

You are WRONG....A21 is class A up to 8 w....

From Ken Stein review, 2007
In these Parasound amplifiers both the positive and negative transistors for each channel are always fully on – the definition of Class A operation - up to 8 watts output per channel. So, for the first 8 Watts of power, which exceeds the typical average power requirements for music, the output transistors are always on. For greater than 8 Watts, the transistors are in class A/B operation where they are partially on when they're not up for duty and fully on when they are up for duty.

And my mains are 8 ohm, 91 db...so very easy to drive.

 

[Irvrobinson]

You are WRONG....A21 is class A up to 8 w..

Eight is a few. (For those who don't know, the A21 is rated at 250w/ch into 8 ohms.)

 

[highfigh]

Eight is a few. (For those who don't know, the A21 is rated at 250w/ch into 8 ohms.)

3 is a few, 8 is a small mob.

 

[Irvrobinson]

3 is a few, 8 is a small mob.

Not when watts are concerned.

 

[PENG]

You are WRONG....A21 is class A up to 8 w....

From Ken Stein review, 2007
In these Parasound amplifiers both the positive and negative transistors for each channel are always fully on – the definition of Class A operation - up to 8 watts output per channel. So, for the first 8 Watts of power, which exceeds the typical average power requirements for music, the output transistors are always on. For greater than 8 Watts, the transistors are in class A/B operation where they are partially on when they're not up for duty and fully on when they are up for duty.

And my mains are 8 ohm, 91 db...so very easy to drive.

You are not exactly wrong but Irv was right. He said "Parasound is just using audiophile double-talk with that Class A/AB designation."

If you only need an average of 0.1 to 0.2W or less like I do, then there is a good chance your A21 could stay in class A, otherwise it will kick into class AB mode during peaks for sure. The A21 really is a 250W (8 ohms) class A/B amp for all intents and purposes.