jbeard Posted May 27, 2009 Share Posted May 27, 2009 I have a pair of Forte I's upgraded with Bob Crite's crossovers and tweeter diaphragms. I was wondering if anyone might have a recommendation for a great integrated SET amp to drive them with. I prefer musicality over neutrality. I want to experience the epitome of SET. My budget is somewhere below $2000. Anyone in the Central Arkansas area with a setup I might be able to hear? Thanks in advance for the help! Quote Link to comment Share on other sites More sharing options...
leok Posted May 27, 2009 Share Posted May 27, 2009 You might consider trying SET rather than buying. SET amps tend to be no feedback designs with high impedance outputs. The Forte (and Chorus) speakers (I've used both with SET amps) have impedance (or efficiency) peaks in the midrange and amps with high impedance outputs will accentuate that region resulting in what is often referred to as a "shouting" quality to the sound. I have 2 tube no-feedback amps and found both unuseable with the Forte or Chorus designs (I've had the -II versions of both). Both of those tube amps work well with my RF-7s. I recommend a ss amp with low distortion at low power for the Forte and Chorus. I am happy with a Crown D-45 which will cost you less than half of your $2K budget. It is designed to be used with high efficiency horn loaded loudspeakers. I'm not saying don't try SET with the Forte. The clean sound of SET is attractive, but the coloration eventually got to me. Leo Quote Link to comment Share on other sites More sharing options...
jbeard Posted May 28, 2009 Author Share Posted May 28, 2009 Thanks Leo. I am currently running a Scott 299a and find the sound to be awsome. Does the Scott 299 have a high impedence output similar to a SET? I was really just looking for another toy to play around with more than anything. I completely agree with your recommendation to try the setup before investing in one. Quote Link to comment Share on other sites More sharing options...
leok Posted May 28, 2009 Share Posted May 28, 2009 It would be interesting to compare SET with the Scott. The Scott has a relatively low impedance output due to the use of feedback, so you will get a good frequency response (not "shouty"). The lack of feedback traditionally in SET designs is one reason for SET's very high impedance output. However, feedback can have its own sonic signature (possible distortion of sibilances among other things). I encourage you to try a pair of SET amps if you can. You can listen through the frequency response variations and hear a clarity that comes with a no feedback design. Leo Quote Link to comment Share on other sites More sharing options...
djk Posted May 28, 2009 Share Posted May 28, 2009 The impedance peak causing the problem with the SET can be flattened with a simple LCR network that may be external to the speaker. Having said that, the Forte will probably need more power than an inexpensive SET has (unless you listen very quietly). Quote Link to comment Share on other sites More sharing options...
jbeard Posted May 28, 2009 Author Share Posted May 28, 2009 djk, I am not familiar with a LCR network. Could you please provide some additional information? Also, I have found an integrated 300B SET that produces 8 watts/channel. What do you think a good minimum would be in terms of SET power? Quote Link to comment Share on other sites More sharing options...
SET12 Posted May 28, 2009 Share Posted May 28, 2009 I have a pair of Forte I's upgraded with Bob Crite's crossovers and tweeter diaphragms. I was wondering if anyone might have a recommendation for a great integrated SET amp to drive them with. I prefer musicality over neutrality. I want to experience the epitome of SET. My budget is somewhere below $2000. Anyone in the Central Arkansas area with a setup I might be able to hear? Thanks in advance for the help! If I had 2K to spend it would be these http://www.pacificvalve.us/MD3008A.html If you haven't heard one, be prepared for a shock. I certainly have a different opinion of what a SET amp can do for Fortes as well. http://www.audiokarma.org/forums/showthread.php?t=159340 SET12 Quote Link to comment Share on other sites More sharing options...
jbeard Posted May 29, 2009 Author Share Posted May 29, 2009 Set 12, I was hoping you might comment. I have read your thread and am ver impressed by your SET's. Do you have a thread on your build? How much did these cost to build? Some previous comments have warned about impedence issues. What's your take? What do you know about this LCR network that was recommended? Quote Link to comment Share on other sites More sharing options...
Colin Posted May 29, 2009 Share Posted May 29, 2009 I think you have already heard some pretty good amps with your speaks. Yet you are still looking for something more. I would consider Juicy Music pre-amps with NOSvalves VRD tube amps. Quote Link to comment Share on other sites More sharing options...
djk Posted May 29, 2009 Share Posted May 29, 2009 "I am not familiar with a LCR network. Could you please provide some additional information? " L=0.326mH http://www.madisound.com/catalog/product_info.php?cPath=404_20_30&products_id=970 C=16µF http://www.madisound.com/catalog/product_info.php?cPath=404_5_304_7&products_id=133 R=6R8/10W http://www.madisound.com/catalog/product_info.php?cPath=404_86_87&products_id=217 "Also, I have found an integrated 300B SET that produces 8 watts/channel. What do you think a good minimum would be in terms of SET power? " That might be OK for most use, but it's not going to get real loud. It largely depends on the music, room, and you. For me I would want 100W on the Forte in a moderate sized room (for BIG classical music). Quote Link to comment Share on other sites More sharing options...
SET12 Posted May 31, 2009 Share Posted May 31, 2009 Set 12, I was hoping you might comment. I have read your thread and am ver impressed by your SET's. Do you have a thread on your build? How much did these cost to build? Some previous comments have warned about impedence issues. What's your take? What do you know about this LCR network that was recommended? jbeard, Thanks for your interest in my SET amps. Although of course there is more to just having a great pair of amps to work with. Such as a great front end whether analog or a digital front end. Every thing goes hand in hand IMO. As to my amps I don't have any specfic thread or post on them but I have been asked to post a thread on their build on an overseas forum. My SET amps would be considered very controversial in their design as I don't take the conventional design approach to amplifier design. They are very powerful watt for watt and can hold their own with many modern and vintage amplifiers whether tube or SS and often exceeding either or. My SET amps are designed to be used CD direct eliminating many issues for me. Although they can use line stage preamps I have found only one that I cared for. Often in comparisons of vs direct the direct wins over all and usually by a wide margin. My CDP though dated is heavly modified with a power supply that will rival many home theater recievers with 150,000uf's of supply, it also uses Burson discrete Op Amps and I will be installing a new Burson Clock in the near future to further enhance the players sonics. I have been amazed at comparing this 18yr old player to several $4000 plus CDP's. I am surprised at the interest in my CDP as I look here with some 4000 views http://www.audiokarma.org/forums/showthread.php?t=185971&page=6 My Fortes crossovers are one of the key componentsin my system as well. As for impedance issues I personally don't have any issues with high output impeadance. I find there are other system issues that come into play for speed and control. One is Power supply DCR. When it is high it can make a SET sound lame and loose. As for an example read about this mans work! Which my amps parallel. http://www.enjoythemusic.com/magazine/equipment/0801/fleshandblood.htm Another area is speaker Inductors and I am no fan of Iron Cores, even the most hardy of Iron Cores sounds anemic to me as well as Low AWG air cores used for low frequency drivers. Its a know wonder the 18 and 20AWG's with a 100ft of wire between the amp and the woofer voice coils sound the way they do. If there is anything I have learned its certainly this "That there is no single area that one can point to exclusively and say thats it!." It just all works together and when enough good is working together you have something. As to the amplifiers cost, yes they could be built for under 2K. If you'd like more info do contact me. SET12 Quote Link to comment Share on other sites More sharing options...
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