3 amps for HE speakers

[DieuBlingBling]

Hello everyone,

I am searching for 3 amps to go in a active crossover configuration with a pair very effective speakers (more than 105dB)

The thing is that i would like 3 identical amplifiers.

There will be 2X 12" per side (in isobaric configuration) and compressions drivers for the mid and highs

I have not decided if i want to go with SS or tube (or hybrid) -i am more on the tube or hybrid side but...

The budget for each amp should not be more than 2k or 2.5k

What have get my attention for now :

-Ladyday 300B SET Level 3 Kit
-First watt (but i don't know which one will be the best choose for this configuration)
-An amp made by one of you guys ?

I like the last idea as we can discuss about cool parts to put inside


So if you have suggestions let me know

Thanx

[mashaffer]

Hmm... this could be an interesting project. That price range gives you a lot of options. Have you settled on crossover frequencies? Do you have a crossover or do you intend to build that as well? What are you using as a preamp? Why do you want the amplifiers to be identical rather than optimized for their particular task?

I have a few thoughts based on the information that you have given so far.

As I understand you want to build three separate stereo power amps to drive their respective drivers on both sides right?

1. If you are using horns for the mids and treble then I think the 300s are probably overkill unless you have a pretty large room. You could go with something a bit less expensive and use the money saved to make a nice tube crossover and preamp.

2. I would definitely consider SET for the midranges. I think that you definitely want to go triode or triode mode here.

3. The treble amp could be SET or a nice clean low power PP. When the fundamental frequency is on the order of 5KHz and above the high order harmonics are of relatively little consequence as even the third harmonic is above the limits of human hearing.

4. For the woofer amp I would strongly consider a moderately powered triode PP amp; possibly with a smidgen of feedback to help keep the woofers under control. Even with high efficiency woofers the majority of headroom requirement is going to be on the woofer amp. If you wanted to go SET here then this is the one amp where the 300 might be worth the extra money.

just my two cents.

[DieuBlingBling]

Hello Mashaffer

Originally posted by mashaffer
Hmm... this could be an interesting project. That price range gives you a lot of options. Have you settled on crossover frequencies?

Not already, i am expecting my new drivers, i organize everything for that purpose

Do you have a crossover or do you intend to build that as well?


I intend to use an active crossover

What are you using as a preamp?

I have a Shindo preamp , so quite colored (but in a particular way)

Why do you want the amplifiers to be identical rather than optimized for their particular task?

In fact it is just assumption that made me choose this path.

I presume that mixing different amps can product weird result on the overall coherency , phase, time rise

But as i said it is just assumptions



I have a few thoughts based on the information that you have given so far.

As I understand you want to build three separate stereo power amps to drive their respective drivers on both sides right?

Exactly

1. If you are using horns for the mids and treble then I think the 300s are probably overkill unless you have a pretty large room. You could go with something a bit less expensive and use the money saved to make a nice tube crossover and preamp.


2. I would definitely consider SET for the midranges. I think that you definitely want to go triode or triode mode here.

3. The treble amp could be SET or a nice clean low power PP. When the fundamental frequency is on the order of 5KHz and above the high order harmonics are of relatively little consequence as even the third harmonic is above the limits of human hearing.

Intresting, and what would be the advantage of a PP design on the highs frequencies ?

4. For the woofer amp I would strongly consider a moderately powered triode PP amp; possibly with a smidgen of feedback to help keep the woofers under control. Even with high efficiency woofers the majority of headroom requirement is going to be on the woofer amp. If you wanted to go SET here then this is the one amp where the 300 might be worth the extra money.

okay i don't comment every suggestion as for now i will just listen

just my two cents.

I imagine that many of you have tried the same amp at all stage and different ones at all stages

What are the advantages of each solutions ?

----

Futhermore as i am on Diy audio and i ask for the electronics, do you think that a noobs on amps can achieve this kind of work ?

It appears to me like something over the top for me

Honnestly i prefer to ask you guys for the electronics part as i will do the speakers, so don't get angry with me for my lazyness


Thanx for your post Mashaffer

[kenpeter]

Isobarik (lose 6db's) 12's with 105db efficiency do not exist.
Unless you are planning bandpass, Karlson, or Horn loading.

Even then, I think that your low amp will need to be more
powerful than the other two (and bigger iron capable of
the lowest frequencies without saturation).