Suggestions for RIAA preamp?

[coldcathode]

It is a Creative external sound card. I get less than 1V at the outputs.

[makeb4break]

human hearing and music reproduction is two very different things. a lot is explained in that thread i linked to. while your thoughts are valid, it's really not a subject for this forum. i can say that i've never heard a mono sub fully integrated in any setup and very few stereo subs that did any good. and those that did where cut at 40-50Hz (and steep!) and helping out what was essentially fullrange speakers

1V (RMS?) should be enough for most (power) amps

my advice it to put some money into a decent DAC before doing a SET for your sub(s)

[makeb4break]

also, a high sensitivity woofer needs a VERY large enclosure to do any good. depending on design it may not even do any real sub'ing. a high Z ouput SET is a rather poor choice for this

while you may need 1W _average_, you'll still need some headroom (i like 20dB) for real music (<-- yes yes modern music is compressed like crap, i know)

[Eli Duttman]

I would like to stay "Octal"

Off the top of my head, 3 types are candidates for the 1st gain block position: the 'SL7, the 'SJ7, and the 'AC7. You'll get a better price buying "12" V. heater versions and regulated 12 VDC supplies are very easy to build.

While the pentodes might be marginal in the noise factor dept., you don't have worries about adverse Miller capacitance/cartridge interactions.

With approx. 20 dB. gain in the line stage, a 'SN7 seems feasible in the 2nd gain block position.

[coldcathode]

Originally posted by makeb4break
also, a high sensitivity woofer needs a VERY large enclosure to do any good. depending on design it may not even do any real sub'ing. a high Z ouput SET is a rather poor choice for this

while you may need 1W _average_, you'll still need some headroom (i like 20dB) for real music (<-- yes yes modern music is compressed like crap, i know)

Make,

I just got in to the group buy for Pete Millet's Xover boards. They are 24db/Octave.

You are correct though,
1: Probably going to need about 20Watts
2: Probably going to go PP pentode w/???
3: 3/db down point will be more like 80hz and it will be a BIG box and bandpass at that to be REALLY STEEP.

To move back to the threads original topic:

I think what I am going to do since I have the PS for it is adapt the cornet schematic for the phono section and then add 2 more channels to the preamp. From there I can then decide what to do with the xover board.

I had being playing with the idea of the tube xover for like a year now. When the group buy came up today I am starting to "rethink" the whole setup.

Maybe I will just have to look at a "bi-amped" speaker project.
Any suggestions as to "affordable" drivers that can play down in the 20hz range?

I have pretty good skills with enclosure design & construction so a DIY set of speakers is not an issue. It's just that drivers can get up into some hefty cost.

[makeb4break]

Originally posted by coldcathode


Make,

just call me mb4b

24dB/oct is fine for the sub, but i'd cross your you main speakers at 6dB/oct, just using a a single cap

are u going to do new speakers or what? i'm a little confused

[coldcathode]

MB4B,

The group buy on the Millet Xover board came up out of nowhere. I had always been toying with the Idea of building an all tube crossover. So this "throws a wrench in the works" so to speak.

I think what I will do now is look into building my own Speakers. I have a LOT of experience with box building and passive networks etc after years in Car Audio. What I am thinking is to build a "3 Way" system. I would Bi-Amp a set of monitors using the Millet Board 2-Channel 2-Way.

The low pass channel would then be split 1/2 would be summed mono after a passive Xover to whatever F3 I choose for the sub, and the other half 6db Passive High pass at the input of the "mid" amp.

What I am wondering is if anyone has a suggestion for decent drivers, where to buy and a good starting point for driver size and type based upon a smallish (11x14) room? Power for would be in the 8-10 watt range PP.

[athos56]

I currently use a B&C 8PE21 8" midrange. I run it full range and get a fairly flat response in a small sealed box. Low enough to crossover to a good sub and high enough to crossover to a small format compression driver (~3 to 4kh). For the compression driver I like the small BMS drivers and a simple round horn.