3dzapper Posted November 6, 2003 Share Posted November 6, 2003 Hey guys I think you are right. I just got through building up my 300b set amp. After a proper time on the Variac it was time to test it out. I hooked it up to the Heresys with a Greatful Dead CD and from the first drum beat I knew that this was a winner. Then I put it on the Klipschorns, and with a relitively stock Dynaco PAS 3, and vinyl. The first was Jackson Browne "The Pretender", Crystal clear, just like in a club in Newport. Now Jim Croce's "I've Got A Name", agian crystal clearity, only some of the songs are poorly recorded on this album and the SET shows every flaw as it should. Now "Lionel Hampton In Newport" makes you want to swat the mosquitos! There is just a bit of siblance which I attribute to the new EH 300b gold grids needing to break in. It also has a pair of NOS RCA 6SN7GBs and a 5U4GB rectifier. The only previous SET experience I've had was with a small EL84 SE amp ( I can't say SET because I don't know if is wired in triode) and I found it lacking in bass and power. I wanted 300bs because of the tremendously powerful 8 Watts to drive the Khorns to concert levels. The bass is right there where it belongs with this amp. I am very happy with the returns on the $600 investment in this amp. When I get more Paypal credits I'll try some tube rolling and see just how good this thing can get. Just thought you guys would like some positive feedback for a change. Rick Quote Link to comment Share on other sites More sharing options...
NOSValves Posted November 6, 2003 Share Posted November 6, 2003 3D, Great job I hope your having fun it sure seems like you are ! Did your ever get the other project done ? I bet old Kelly is almost afraid to open this thread by the title LOL !! Craig Quote Link to comment Share on other sites More sharing options...
Parrot Posted November 6, 2003 Share Posted November 6, 2003 Super looking, Rick. Quote Link to comment Share on other sites More sharing options...
BigBusa Posted November 6, 2003 Share Posted November 6, 2003 3D awesome to hear you're enjoying it! A couple questions ,,,the right tube looks like it's about to fall out! Straighten that up will ya? Is the power switch lighted? Quote Link to comment Share on other sites More sharing options...
Randy Taylor Posted November 6, 2003 Share Posted November 6, 2003 Hey ! that 300B amp looks nice , what kind of amp is it, and you bought this amp for $600. was it a kit, where did you buy it? Quote Link to comment Share on other sites More sharing options...
3dzapper Posted November 6, 2003 Author Share Posted November 6, 2003 No Craig I was anxious to get the HF81 and this one done. Next up is the 299C and the Alps as per your excellent advice. Then I have to put one in the Dyna PAS 3. Any advice about recapping that pre? BB, yea it's not straight but I can't do anything about it right now. Something about 500VDC that scares me.(LOL) I'll adjust the socket when the newness wears off. No the light in the switch is not hooked up. I figure the red on indicators in the tubes are enough. Quote Link to comment Share on other sites More sharing options...
Painful Reality Posted November 6, 2003 Share Posted November 6, 2003 Nice amp. Looks like a 6SN7. Is it a JeLab 300B, a Reichert Flesh and Blood or the Classic 300B from JC Morisson? Congratulation on this project. Quote Link to comment Share on other sites More sharing options...
3dzapper Posted November 6, 2003 Author Share Posted November 6, 2003 OK here is the story. I bid on this amp on eBay from a guy who called himself Thermo-electron. I got the bid for $421. I figured the parts alone were worth this or more. After I won the bid I recieved several emails warning me about this guy but I decided to Paypal him and see what would happen. Appearantly the guy would sell something on eBay then buy the parts and "build" it. After a month and a half and several emails the thing finally came. It was "assembled" with the empasis on the first sylible. Every joint was a cold solder joint. Wires of dubious quality burned through with a solder gun. He used what appears to be that lead free solder that melts at about the temperature of the surface of the sun. But nice quality iron and parts. The only thing that I could do is take the thing appart and rebuild it with quality silver plated wire and silver bearing solder The design is based on the JE Labs version except on one chassis so it was easy to build back up. It took about 10 hours over 3 days. It is sounding even better as it breaks in DSOM was awesome! Never heard it better. Now playing a Van Morrison CD, I got tired of getting up and down to change sides. This a before picture I'm pointing at a resistor junction that is not soldered at all. I'll post the after below. Rick Quote Link to comment Share on other sites More sharing options...
3dzapper Posted November 6, 2003 Author Share Posted November 6, 2003 Here is the chassis after I was done with it. Well not quite, I am going to change out those cheap plastic binding posts in a few days. Rick Edit: 8 Watts max. 102db at listening position not breaking a sweat. Quote Link to comment Share on other sites More sharing options...
leok Posted November 6, 2003 Share Posted November 6, 2003 Nice amp. I haven't heard a 300B, I'm sure they're great. SET is such clean sound. Just think what it will be in a few months. leok Quote Link to comment Share on other sites More sharing options...
Painful Reality Posted November 6, 2003 Share Posted November 6, 2003 Plenty of room in this chassis to have fun. If interested in doing mods and all, you might consider switching the amp to a Western Electric model 91 clone. It is still one of my favorite 300B amplifier out there. You have a schematic of the amp here: http://www.angela.com/catalog/how-to/angela_model_91/schematic.gif. Quote Link to comment Share on other sites More sharing options...
jazman Posted November 6, 2003 Share Posted November 6, 2003 3d, Congratulations on a job well RE-DONE. 8 wpc, and Khorns! I applaud your move to expand your audio experience. You've also demonstrated that it does not require megabucks to experience the joys of SET. I also expect you to fully enjoy your PP 299C project. The bottom line is always........... Enjoy the music! Klipsch out. Quote Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted November 6, 2003 Share Posted November 6, 2003 Jazman, Speaking of enjoying the music, did you ever pick up on that Dolphy with George Russell album "Ezzthetics" ? Bet Dolphy would sound amazing on your SET driven new Khorns! C&S Quote Link to comment Share on other sites More sharing options...
Tom Mobley Posted November 6, 2003 Share Posted November 6, 2003 painful, you like that design? seems like (to my inexperienced eye) there are lot of parts around the driver and 300b. is all that stuff necessary and/or good? I've seen pics of SET amps that had very few parts, I thought that was good? Shed a little light here, is this a different but equal design strategy or maybe one that just conveniently lends itself to what he already has? expiring minds want to know, and in my case SET is now a real possibility. I'm a DIY kind of guy so I'm interested in these designs. Tom Quote Link to comment Share on other sites More sharing options...
3dzapper Posted November 6, 2003 Author Share Posted November 6, 2003 jazman. "Enjoy the music!" You've got the world by the holes right there. Rick Quote Link to comment Share on other sites More sharing options...
mike stehr Posted November 6, 2003 Share Posted November 6, 2003 Christ, I suppose I better get my 300B up and going. I got about half-way, and then put it off..... I do need to get it done. Quote Link to comment Share on other sites More sharing options...
Painful Reality Posted November 6, 2003 Share Posted November 6, 2003 ---------------- On 11/6/2003 9:36:16 PM Tom Mobley wrote: painful, you like that design? seems like (to my inexperienced eye) there are lot of parts around the driver and 300b. is all that stuff necessary and/or good? I've seen pics of SET amps that had very few parts, I thought that was good? Shed a little light here, is this a different but equal design strategy or maybe one that just conveniently lends itself to what he already has? expiring minds want to know, and in my case SET is now a real possibility. I'm a DIY kind of guy so I'm interested in these designs. Tom ---------------- First, a low part count is not a sure recepy for success. My favorite amp, The Tenor OTL is far from being simple inside... In the model 91 case, it is a really simple desing. You may get confused by the "additional parts" for the screen supply. The sound of a Pentode driving a DHT is quite "haunting". Jean Hiraga in "Initiation aux amplis à tubes" related this to the smoothly decreasing profile lower odd order and high order distortion. Thorsten tried to quantify this in http://www.fortunecity.com/rivendell/xentar/1179/theory/300bampdistortion/300BAmpDistortion.html. I will say: "it sound darn good". The Model 91 is still one of my favorite 300B amp. Quote Link to comment Share on other sites More sharing options...
Deang Posted November 6, 2003 Share Posted November 6, 2003 I like lead free solder, it's all I use now. I'm doing solder lugs on crossovers however, so I can get away with more heat. Congrats, keep those K-horns shaking! Quote Link to comment Share on other sites More sharing options...
3dzapper Posted November 6, 2003 Author Share Posted November 6, 2003 Dean, Did you ever try silver bearing solder? It flows soo nice and leaves a nice clean shiny joint. You can pick some up at Radio Shack for just a couple of bucks to try. Believe me you'll love it. And, if you are soldering on any gold ends you need it according to something I read someplace. (It's tough being over the speed limit.)Bad case of CRS. Rick Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted November 6, 2003 Share Posted November 6, 2003 Excellent job, Rick. Looks like some really nice workmanship within as well. More importantly, you are getting some good results with the 300B. That is one of the great times of satisfaction when you get a new amp going that transscends what you were listening to causing the great "pull out all the records" exodus. Audrey has been out of town all week doing Outward Bound in the NC mountains and this place has been RINGING all day and not with noise! I had TWO great happenings this week. First, I got my 2A3 Moondogs going again after enjoying my PP EL-34 amp for awhile. This was a re-awakening yet again as ye olde aural memory was getting hazy. The second GREAT happening for me was our University selling a load of vinyl from my old college radio station - this almost brought tears to my eyes as I ran down there for 20 cents a record and bought everything I could find that I loved. This stuff is impossible to find. And I have been sitting here with them all over the house playing day and night. Man, it's been great. AS an aside, I have some pics of a WE-91 300B that Jeff built somewhere on my hard drive. I'll post a few shots. kh Quote Link to comment Share on other sites More sharing options...
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