will a 45 DHT amp work with 96 dB speakers

zobsky

fringe lunatic
thinking of something to design and build this summer, .. will a flea power 45 amp work with 6.5" fostex single driver speakers (about 96 dB efficient). i'm familiar with all the theories about wanting enough headroom to hit 110 - 120 dB but wanted to know from anyone who's actually been in this situation.


TIA :thmbsp:
 
I drive FE108's with a 7591 SE amp and they can blast you out. Cabinet design is very critical to acheiving high sound levels.
 
Shouldn't be a problem driving them at all. Welcome back. You have been to India since we last spoke haven't you?
If the SE 7591 is triode strapped I would imagine the wattage to be very close to a 45.
 
Thanks for all the advice.

judging from the replies, It seems that they will work.

when i do get started, i will attempt to make this amp a thing of beauty, unlike my other beastly looking projects :)

hope yo're enjoying your role as moderator, Thatch. Work has kept me busy and out of the DFW audio scene for a few months now, but I hope to be back soon.
 
I can tell you that Fostexes as you describe will work very well with a 2A3 amp (3.5w). A 45 will be a bit less powerful, but I suspect it'll be a good to very good match anyway. The 'headroom' argument (IMO) needs to be tempered by two things:

1) your taste in music. The combo might not do it for you playing Holst's "The Planets", but might be all you'd ask for playing Joni Mitchell's "Blue" or small combo jazz, or even a string quartet.

2) Remember that tubes tend to compress before they raunchily clip... the 'compression' phase of operation may buy you a dB or two and you may not mind (or maybe not even notice).
 
mhardy6647 said:
1) your taste in music. The combo might not do it for you playing Holst's "The Planets", but might be all you'd ask for playing Joni Mitchell's "Blue" or small combo jazz, or even a string quartet.


thanks for the advice,

the point you make is moot, as these drivers (FE 166E) are happiest with lighter music anyway (even in the back horns they are in), regardless of the amp. .. horses for courses kinda thing :)

i could always substitute 2a3 tubes in and add a switch to change the bias if required.
 
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Hi MikE,
The Edgarhorns are gone but another horn-loaded 3-way is in the mix. Not as elegant as the Edgarhorns but just as efficient.

I have many irons in the fire currently with audio gear all over at friends homes, better to loan out the gear I am not using than have them sit around collecting dust.

I finally have a JBL/Altec system back like my avatar but with all 8 ohm impedance, 902 Altec driver with tangerine phasing plug and modded/upgraded crossover.

Sound is still not up to par, but still breaking in 2226H driver I am using. With only 75 wpc Sansui 7900(EW magic applied), still takes time to break in a 600 watt midbass driver. Potential is there though.

Ron
 
Hey guys...

long time no type :) Hope all's well *is that a word???*


Zobsky...in most instances at a decent listening level, you should be fine with the glorious sounding 45.

take care all...(you tube MikE) :thmbsp:


dan
 
gonefishin said:
Hey guys...

long time no type :) Hope all's well *is that a word???*


Zobsky...in most instances at a decent listening level, you should be fine with the glorious sounding 45.

take care all...(you tube MikE) :thmbsp:


dan
thanks Dan,

In keeping with my fringe lunatic tendancies :screwy: , does anyone have any experience with the similar (but somewhat cheaper) type 46 tube? The guys at AA seem to endorse it.

cheers
 
46 sounds very nice. Less power than a 45 but that nice DHT cream (as Dr. Gizmo useta say). Gary Kaufman, James Melhuish and I all three set out to build 46 amps a few years ago. Gary built a very nice 'convertible', James built a DRD (direct coupled) amp a la Jack Eliano... and me? Well, I've got 4 NOS ST-shape 46's and a very nice box of parts in the basement :-( Fortunately, Gary & James don't make too much fun of me.

Gary's "ragtop":
http://www.the-planet.org/Ragtop.html
Ragtop.jpg


James' DRD:
http://www.melhuish.org/audio/46amp.html
JM46amptesting2.jpg


EDIT: Note that the 46 is a dual grid, directly heated tube. IIRC, the RC-10 or some old RCA manual recommends using a 46 to drive a pair of parallel (?) connected 46's as a Class B (?) amp. Check this before you believe me!
 
mhardy6647 said:
Gary Kaufman, James Melhuish and I all three set out to build 46 amps a few years ago.

now that's keeping some fine company in that circle of three :yes:


MikE said:
Did you notice there's a new sheriff in town? Take care old friend. MikE

:jawdrop: well...I noticed now. I guess I just looked on at the posts...even the stickies had changed (good thing I'm not a detective :eek: )

All that is left to say is...MikE, congrats on a job well done over the years...it's been a road I've enjoyed traveling ;) thank you :)

Thatch...congrats on becoming the new Tube Moderator. Mike's torch (<---get it) is certainly in good hands :thmbsp:


dancing banana's for everyone!
:banana: :banana: :banana: :banana: :banana: :banana:


dan
 
zobsky said:
thinking of something to design and build this summer, .. will a flea power 45 amp work with 6.5" fostex single driver speakers (about 96 dB efficient). i'm familiar with all the theories about wanting enough headroom to hit 110 - 120 dB but wanted to know from anyone who's actually been in this situation.


TIA :thmbsp:


In a closet maybe ;) :banana: Just couldn't help myself :naughty:
 
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okay, I scored a pair of 46 tubes on ebay for the princely sum of $14 (one a kenrad and the other a tungsol IIRC, both test about equal and should do fine for prototyping, I'll worry about getting similar tubes later on. ..). I now need to investigate amplifier topologies,

I already have a few leads from this thread and other forums. Feel free to chime in with any ideas.

thanks
 
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Mike Stehr said:
It'll be easier than the RCA 801A's I have.....
What a wonderful tube! You should get about the same amount of power as a 45.
If anyone is interested, former moderator MikE uses 45s to drive 92 db speakers.
 
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