dsavitsk
MOT: ECP Audio
- Joined
- Aug 3, 2003
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I am about to embark upon the building of a new preamp. I am currently using a solid state buffered passive design, and while it is okay, I am not quite thrilled with it. I also have a Melos that has seen better days, and that I am not really thrilled wthanyway. So, I am looking for something that is warm and liquid and full, and would welcome help in deciding what exactly to do. As background, I am pretty comfortable reading schematics, but I do have a lot to learn. As such, while I would like to end up with a preamp that I am happy with, I also intend this as a learning process.
Here are some of the projects I am considering, as well as reasons for or against them. Note that these are all tube designs. I have heard a lot of solid state equipment, including a lot of mega buck stuff, and I just don't like solid state. Even accepting the premise that a solid state pre can sound as good or better than a tube one, I don't want to build one.
So, any help with either choosing one of these, or with other ideas would be appreciated.
Bottlehead Foreplay III
The good: People seem to rave about this. It is cheap, seems easy, and can be tweaked. There is a community for help, and Doc B even offers to fix builds gone bad.
The bad: I am not a fan of dual stepped attenuators, but replacing them leaves a hole in the chassis requiring a whole new chassis to make it look nice. The point is that the design does not quite match my interests. Further, the basic design involving a cathode follower seems to be much maligned. Last, I find the whole Bottlehead sex motif kind of stupid.
Audio Electronic Supply AE3
The good: Dennis J. Had. I am a huge Cary fan, and everything Dennis touches seems to have some sort of magic about it.
The bad: Just plain ugly requiring a new chassis to be designed. This is not necessarilly bad except it means paying for a chassis in the kit that I won't use. Also, see the same critique about the circuit as with the Bottlehead.
Pete Millett's low mu design
Pete says nice things about the design and suggests that it corrects the problems that seem to be inherent in some of the other designs, but the voltage is high enough to give me pause. Further, the fact that I have not seen any information of anyone else ever building this, I am concerned that getting help will be difficult (though I know from experience that Pete is a really helpful guy.) Further, it looks like this can be done for $400-500?
Welborne ultraPath
The good: Tried and tested implementation of this design. Also, since it is available as a nude kit, I could skip the tacky case.
The bad: the batteries would have to go, which means building a PS and paying for batteries I won't use.
Original UltraPath
The good: More of an opportunity to experiment with my own stuff. I have a couple of high quailty 7308's (amperex PQs) around that I would like to use, and it might be fun to design around them. people seem to only have great things to say here. This also presents the opportunity to experiment with low voltage tubes (12ae6a) which might be fun?
The bad: lots of work to modify a circuit I am not sure I understand which presents ample opportunity to screw something up.
Buffered passive pre -- Cathode Follower:
I have already been working on this design. Not necessarilly considered the highest of fidelity, but also really cheap to build. Further, it would only use one tube which would free up the second of a match pair for ... a second preamp I guess. Seems dumb to split up a matched pair of amperex pq 7308's.
Borbelly Hybrid (at Wellborne)
The good, another tried and tested design that is easy to build. Also, it will power phones (Grados) which would really be a nice plus. I am not sure that any of the other designs can do that.
The bad: It does not strike me that I am going to learn that much stuffing a PCB. Further, I am opposed to the SS output section, and people seem to claim this design sounds dry making it not ideal for me. Also, it isn't actually for sale yet, though since building won't begin for a few months that might not actually be a problem.
5687 based preamp
The good: cheap, easy?, people seem to like it.
The bad: There is not really that much information that I can find. Further, this seems to be about the tube, and not the circuit, which is intellectually not very interesting.
Edit: as a final thing, I suppose I should mention associated equipment. Sources are a Cary CDP and a Linn table (though I am between phono stages right now -- I'll probably end up with the Bottlehead). Power amps are either an old Sumo mosfet based amp, a Gainclone, or a tripath based amp from 41Hz (these rotate in and out). Speakers are B&W.
-d
Here are some of the projects I am considering, as well as reasons for or against them. Note that these are all tube designs. I have heard a lot of solid state equipment, including a lot of mega buck stuff, and I just don't like solid state. Even accepting the premise that a solid state pre can sound as good or better than a tube one, I don't want to build one.
So, any help with either choosing one of these, or with other ideas would be appreciated.
Bottlehead Foreplay III
The good: People seem to rave about this. It is cheap, seems easy, and can be tweaked. There is a community for help, and Doc B even offers to fix builds gone bad.
The bad: I am not a fan of dual stepped attenuators, but replacing them leaves a hole in the chassis requiring a whole new chassis to make it look nice. The point is that the design does not quite match my interests. Further, the basic design involving a cathode follower seems to be much maligned. Last, I find the whole Bottlehead sex motif kind of stupid.
Audio Electronic Supply AE3
The good: Dennis J. Had. I am a huge Cary fan, and everything Dennis touches seems to have some sort of magic about it.
The bad: Just plain ugly requiring a new chassis to be designed. This is not necessarilly bad except it means paying for a chassis in the kit that I won't use. Also, see the same critique about the circuit as with the Bottlehead.
Pete Millett's low mu design
Pete says nice things about the design and suggests that it corrects the problems that seem to be inherent in some of the other designs, but the voltage is high enough to give me pause. Further, the fact that I have not seen any information of anyone else ever building this, I am concerned that getting help will be difficult (though I know from experience that Pete is a really helpful guy.) Further, it looks like this can be done for $400-500?
Welborne ultraPath
The good: Tried and tested implementation of this design. Also, since it is available as a nude kit, I could skip the tacky case.
The bad: the batteries would have to go, which means building a PS and paying for batteries I won't use.
Original UltraPath
The good: More of an opportunity to experiment with my own stuff. I have a couple of high quailty 7308's (amperex PQs) around that I would like to use, and it might be fun to design around them. people seem to only have great things to say here. This also presents the opportunity to experiment with low voltage tubes (12ae6a) which might be fun?
The bad: lots of work to modify a circuit I am not sure I understand which presents ample opportunity to screw something up.
Buffered passive pre -- Cathode Follower:
I have already been working on this design. Not necessarilly considered the highest of fidelity, but also really cheap to build. Further, it would only use one tube which would free up the second of a match pair for ... a second preamp I guess. Seems dumb to split up a matched pair of amperex pq 7308's.
Borbelly Hybrid (at Wellborne)
The good, another tried and tested design that is easy to build. Also, it will power phones (Grados) which would really be a nice plus. I am not sure that any of the other designs can do that.
The bad: It does not strike me that I am going to learn that much stuffing a PCB. Further, I am opposed to the SS output section, and people seem to claim this design sounds dry making it not ideal for me. Also, it isn't actually for sale yet, though since building won't begin for a few months that might not actually be a problem.
5687 based preamp
The good: cheap, easy?, people seem to like it.
The bad: There is not really that much information that I can find. Further, this seems to be about the tube, and not the circuit, which is intellectually not very interesting.
Edit: as a final thing, I suppose I should mention associated equipment. Sources are a Cary CDP and a Linn table (though I am between phono stages right now -- I'll probably end up with the Bottlehead). Power amps are either an old Sumo mosfet based amp, a Gainclone, or a tripath based amp from 41Hz (these rotate in and out). Speakers are B&W.
-d
