I need a amp (Observations from a new guy)

[geezerrocket]

Hello all, I am new to this forum and high efficency speakers. My current rig which I intend to keep, consists of all modded or highly modded gear to include a Musical Concepts Hafler DH 500 amp, Dynaco PAS 3x pre, Magnepan 12 qr "gunned" speakers, a 90 lb. Lenco L75 table, and a Prima Luna 8 cd player. The Magnepans are like a old whore at the dock's when it comes to power- You can't give 'em enough! So a few weeks ago I heard a friend of a friends rig that was very different than my own though it sounded very special. His gear consisted mainly of Bottlehead amplification in front of home built cabinets (6.5 cu. ft.) housing Great Plains Audio 604-8h11 drivers. When he fired it up I was stunned how organic and right this "old timey" system sounded. It was nothing like the Klipsch Lascala's that I heard in the military so many years ago (Jam a screw driver in your ear). During our informal session I made a few observations; The 604's did a few things better than my modded maggies such as a much wider sweet spot, (you could walk around the room without penalty) better low level resolution, and slightly bigger dynamics. Having said that, the Magnepans were more holographic with a deeper sound stage, and to my ears, better and smoother treble. I understand that associated gear, room, power conditioning etc.. made these comparisons pretty subjective and un-scientific to say the least. So here I am having decided that I can not live without BOTH the Magnepans and the Great Plains 604's. I have however have decided to get the 604-8h 111's instead of the 11's and I will be using a 10 cu. ft. box (thanks to Jay Fisher). The 500 wpc Hafler is probably not ideal for driving that GPA's so I am looking for suggestions. Understand that I know nothing about output tubes, push pull vs. single ended vs chip amp, or how to bias. I do want to stay away from "flea powered" amps like 45's etc.. as I am prone to crank Rush and Sammy Hagar to big room filling levels. I have a budget of $1500.00 US dollars for a used piece of gear. Happy Holidays.

[Cut-Throat]

You probably heard the Klipsch La Scalas with a high powered sand amp, which would explain the screwdriver in the ear.

It's interesting that you have ruled out the 45 amp. Have you ever heard one? It is my amp of choice, I also own a 2A3 amp and a 300B amp and a Push Pull KT88 etc amp. I use Khorn Bass Bins with Altec 1005B horns and 288-16K drivers. BTW - You may decide to change speakers again once you hear the 288 drivers and horns - I did!

I'll tell you what, your best move is to audition as many systems as you can before committing.

So with that, If you would like to audition a great 45 amplifer and see what it can do with 104db speakers, I will offer you an audition in my home. I also live in Minnesota. Pymouth, just 10 minutes west of Downtown Minneapolis. Contact me and we'll set something up.

Here is a Pic of my listening room.

[Steve Mac]

Hello......what is a Magnepan 12?
I've owned Magnepan 2.6,Tympani ID,Tympani IVa and still have a set of Magnepan 3.5's.
In effect...I've been through the best of that product line.
My current system...which is all horns creates a holographic image that
is eons more stunning than the Maggies.

Personally...I would step beyond the 604 into the 811->511->and beyond.
The Maggies take up so much room behind them to sound right that if
they sound right in your room...you must have the room for bigger horns.

[Steve Mac]

BTW - You may decide to change speakers again once you hear the 288 drivers and horns - I did!

+1

P.S. What a beautiful room! Now that's downright purdy!

[geezerrocket]

Your right, I have not heard a 45 amp, or a 2a3. I am just going on what folks tell me about that (GPA 604-8hii, Or iii) particular driver. They say that it can get on with 1.5 wpc but in a small to medium sized room at moderate volumes- I don't know that for sure. I am a neophyte when it comes to tubes, I have much more experience in power capacitor rolling than tube rolling (Love those Jensen 4 poles). As for the mid eighties Klipsch experience, I can't recall what amp was used as I was more than likely well into a barracks drink-a-thon! It probably had more to do with the digital source. As I recall, back in '85 the cd was in it's infancy. I don't have many cd's from that time period that don't sound somewhat compromised ie. compressed and brittle. I would love to hear your set up, and your very kind to offer. I live in the Detroit Lakes area, about 3 hours N.W. of you. I do however get into the Twin Cities about every week or so with my job (riding big choo choo's from Fargo to Fridley). Maybe we can work something out after the holiday's. I just wish I could get that sound out of my head, as it would certainly be cheaper. I'm thinking there might be a covert (better half left in the dark) 401k raid in my future. Have a good weekend.

[Cut-Throat]

+1

P.S. What a beautiful room! Now that's downright purdy!

Thanks! - I built it special for the Stereo!

Geezer - Just email me when you'd like to hear my system. At [email protected]

I think you also need to hear some Compression Drivers and Altec Horns with some SET amps. I am a good host as I usually have good wine and beer on hand. I always welcome a fellow audiophile.

I am home most of the time, during the day is fine, evenings are fine too.

[geezerrocket]

Hi Steve-Mac, The Magnepans in question Are the MG 12 QR's with "gunned" mods. I have had various magnepans over the years as well. One thing is for sure, these are light years ahead of stock maggies. The original crossover is in the trash as I could'nt find anyone I hated that bad to give it away to. If you want to know more about them google magnestand. I would print the url, but the moderator says I can't until I have 3 more valid posts.... Hazing the freshman?? To my way of hearing there is more than one way to great sound. That's why I am endeavoring to own a "low efficency current whore" of a rig, as well as a high efficency low powered set up. Nice chatting with you fella's, I can see we're all afflicted with the same sickness that drives our better half to drink!

[Altec Best]

+1

P.S. What a beautiful room! Now that's downright purdy!

I second that !!!

[GM]

Having said that, the Magnepans were more holographic with a deeper sound stage, and to my ears, better and smoother treble.

I have however have decided to get the 604-8h 111's instead of the 11's and I will be using a 10 cu. ft. box (thanks to Jay Fisher).

The 500 wpc Hafler is probably not ideal for driving that GPA's so I am looking for suggestions.

I do want to stay away from "flea powered" amps like 45's etc.. as I am prone to crank Rush and Sammy Hagar to big room filling levels.

I have a budget of $1500.00 US dollars for a used piece of gear.

Happy Holidays.

Greets!

604s are near-field monitors, so 'holographic'/'deep' sound-staging isn't a primary performance criteria. For this you'll need compression horns with the longer their 'throw' (increasing directivity), the 'deeper' their sound-staging, etc. and the further away you'll have to sit to get their full benefit. It's all about perspective. Another way is to use bipole speakers positioned well away from any reflective boundaries, but four 604s and the big cabs required gets a bit pricey for most of us.

JF's cabs were designed for wall/floor loading and a high output impedance source, so if you don't use a similar tube amp, then you'll need the Hafler's high power since the high resistance voltage dividing network required to flatten the speaker's response (baffle step compensation (BSC)) is going to turn it into a low power one by the time what's left of its output makes it to the drivers. Based strictly on a sim, it will be < 100 W which actually will only be enough for moderate listening levels on dynamic recordings since the speaker's effective sensitivity will be down around 92 dB/m.

Since there's a certain coupling synergy between tube (or at least transformer coupled) amps and compression horns, driving the woofer with a high SQ digital amp and the HF horn with a 'flea' power tube amp (assuming it has a 'stiff' enough power supply, i.e. high enough output voltage to handle the fastest transients (its slew rate spec)) can be a 'marriage made in Heaven' if done right, though some will argue that this can only happen if a PP tube is used for the woofer.

Unfortunately, it's not likely to happen for $1500, so the Hafler/BSC seems the quickest/cheapest way to get up n' running. Next up would be a high output impedance (low DF) amp (McIntosh 2105 or similar) in good condition, but don't have a clue if such esoterica is available at this price point.


Happy Holidays and all that jive,

GM

[bowtie427ss]

Next up would be a high output impedance (low DF) amp (McIntosh 2105 or similar) in good condition, but don't have a clue if such esoterica is available at this price point.

A fella should be able to bring home a very nice 2105 for 1k or less with a little shopping around. I'm reasonably sure that the 2100 is electronically an identical amplifier less meters and a fancy faceplate. The speaker switch on the 2105 is a known source of trouble and both expensive to replace and difficult to source. 2100 has a DF spec of 11, whereas that of the 2105 is 10. I'm reasonably sure this difference is the result of the speaker selector switch and it's related additional wiring?