Well the amp is done and here is my impression, The speakers I am using are Fostex 167 in a small BR enclosere . The speakers may not be totaly broken in . all signal tubes are Sovtek. Jensen copper in oil
coupling caps, Rikem ohm resistors. blackgate caps on driver stage
Sprague atoms elswhere.
The sound ... warm ... sweet .. ? NO . sounds a little harsh to me
The low end is poor
It is very detailed , clean, very little hum
I thought it would sound a bit better than it does.
Any one have any sugestions ? thoughts?
I decided to test with pair of B & w and wola one ch much lower than other . The fun never ends Jeff
coupling caps, Rikem ohm resistors. blackgate caps on driver stage
Sprague atoms elswhere.
The sound ... warm ... sweet .. ? NO . sounds a little harsh to me
The low end is poor
It is very detailed , clean, very little hum
I thought it would sound a bit better than it does.
Any one have any sugestions ? thoughts?
I decided to test with pair of B & w and wola one ch much lower than other . The fun never ends Jeff
Hi,
I just completed a JE Labs 300B stereo amp. I used Hammond iron, Riken Ohm resistors, Jensen PIO, ASC oil caps (big and sloshy), and a Sprague Atom 40uf first cap. With TJ300B tubes, this thing puts out a lot of bass. I have B&W DM640's and DM602 S2's. Both speakers put out a lot more punch at low listening levels than my SS amp.
I don't know how 2A3's compare, but I thought that they were almost the same as 300B's with less power. Don't kill me if I'm wrong!! ;-)
I just completed a JE Labs 300B stereo amp. I used Hammond iron, Riken Ohm resistors, Jensen PIO, ASC oil caps (big and sloshy), and a Sprague Atom 40uf first cap. With TJ300B tubes, this thing puts out a lot of bass. I have B&W DM640's and DM602 S2's. Both speakers put out a lot more punch at low listening levels than my SS amp.
I don't know how 2A3's compare, but I thought that they were almost the same as 300B's with less power. Don't kill me if I'm wrong!! ;-)
Just a quick pointer- if you have built the 2001 edition JE labs, it shouldhave fairly good bass due to the cathode follower. I found I much preferred the cathode follower to SRPP.
I would also reommend the other ideas- try some different brands and see how you go.
Also it is fairly depndent on what output trans you use, some are much beter than others.
I would also reommend the other ideas- try some different brands and see how you go.
Also it is fairly depndent on what output trans you use, some are much beter than others.
asprin
Well I just can not listen to the amp very long using the Fostex.
It is very nice using a pair of B&W DM 601. The OPT is hammond 1627se
I think I am going to change the 6sl7gt (Sovtek) with JAN Syl or phil
ps: It is the 2001 edition I just cant figure out why the SS
sounds better with the Fostex , maybe the B&W mask the harshness
of the amp , one thing the 2A3 is more detailed.
Signed : drowning in analysis
Well I just can not listen to the amp very long using the Fostex.
It is very nice using a pair of B&W DM 601. The OPT is hammond 1627se
I think I am going to change the 6sl7gt (Sovtek) with JAN Syl or phil
ps: It is the 2001 edition I just cant figure out why the SS
sounds better with the Fostex , maybe the B&W mask the harshness
of the amp , one thing the 2A3 is more detailed.
Signed : drowning in analysis
From Arnoldc:
What do you mean by slower? Did you use the same components?
Forgive me if I don't understand "tubelese". I'm new to this field and have only heard a Luxman pushpull amp otherwise. I like the way the tube amps bring the stage forward with seemingly more power and presence. I switched back to my Nakamichi PA5-II and noticed how much cleaner and accurate the sound was as compared to my 300B, but not as musical or pleasing. (Uh, I might be a little biased since I made it myself!)
Tenderland,
Are you listening to your set up in a small room? I don't know what a Fostex is, but I do know B&W. With my Nakamichi, my DM602 S2's were lacking in bass and presence. With my tube amp, they came alive and don't need a subwoofer anymore. With my DM640's, the bass goes through the house. I even did the crossover mod that limits the low freqs to the bass drivers. That didn't stop the double bass 30 hz note in the Star Trek sound track from going through.
What do you mean by slower? Did you use the same components?
Forgive me if I don't understand "tubelese". I'm new to this field and have only heard a Luxman pushpull amp otherwise. I like the way the tube amps bring the stage forward with seemingly more power and presence. I switched back to my Nakamichi PA5-II and noticed how much cleaner and accurate the sound was as compared to my 300B, but not as musical or pleasing. (Uh, I might be a little biased since I made it myself!)
Tenderland,
Are you listening to your set up in a small room? I don't know what a Fostex is, but I do know B&W. With my Nakamichi, my DM602 S2's were lacking in bass and presence. With my tube amp, they came alive and don't need a subwoofer anymore. With my DM640's, the bass goes through the house. I even did the crossover mod that limits the low freqs to the bass drivers. That didn't stop the double bass 30 hz note in the Star Trek sound track from going through.
driver replacement
Well I replaced the sovtek 6sl7 with a pair of JAN phillips 6sl7wgt.
HOLY ****
The vocals are not as edgy , it is deeper , Gutair sometimes a little exagerated.
I never heard anything like it using the Fostex speakers.
The Fostex do have there moments but sounds great .
Jeff
Well I replaced the sovtek 6sl7 with a pair of JAN phillips 6sl7wgt.
HOLY ****
The vocals are not as edgy , it is deeper , Gutair sometimes a little exagerated.
I never heard anything like it using the Fostex speakers.
The Fostex do have there moments but sounds great .
Jeff
From Arnoldc
Ah, okay got it. I guess that's the characteristic differences between the two types. Is the 2A3 good for rock? I saw a schematic that switched in a resistor into the filament supply so that a 2A3 tube could be used in a 300B amp.
If the output tube really changes the sound of the amp, it might be worth it. What do you think?
Ah, okay got it. I guess that's the characteristic differences between the two types. Is the 2A3 good for rock? I saw a schematic that switched in a resistor into the filament supply so that a 2A3 tube could be used in a 300B amp.
If the output tube really changes the sound of the amp, it might be worth it. What do you think?
Arnoldc,
You must have very efficient speakers or you go for quality of the sound rather than the volume as a rocker!!
I would not have thought of a SET amp for rock, but a push-pull instead.
So, 2A3 has a faster response, tighter sound than a 300B? I know that the 300B's typical sound is for vocals. I made my selection of tube from Thorsten Loesch's review. Basically, the TJ300B does not follow the characteristic curve of the WE300B. From my listening between different 300B's, this tube has a flatter freq curve and covers the full spectrum.
I should listen to a 2A3 for the differences. My first schematic was for a 2A3, but due to the 90 db/w/m ratings of my speakers, I figured I'd go for the power. No matter where I search, I cannot find any writeups on the differences in tones between the different types of tubes. I see comparisons between different brands of the same type of tube. Hopefully, I will be able to find more information.
You must have very efficient speakers or you go for quality of the sound rather than the volume as a rocker!!
I would not have thought of a SET amp for rock, but a push-pull instead.
So, 2A3 has a faster response, tighter sound than a 300B? I know that the 300B's typical sound is for vocals. I made my selection of tube from Thorsten Loesch's review. Basically, the TJ300B does not follow the characteristic curve of the WE300B. From my listening between different 300B's, this tube has a flatter freq curve and covers the full spectrum.
I should listen to a 2A3 for the differences. My first schematic was for a 2A3, but due to the 90 db/w/m ratings of my speakers, I figured I'd go for the power. No matter where I search, I cannot find any writeups on the differences in tones between the different types of tubes. I see comparisons between different brands of the same type of tube. Hopefully, I will be able to find more information.
Tenderland,
I'm using Sylvania chrome top "Baldwin Organ" 6SN7GTB's. Sounds good. But being a newbie, I can't really say what other tubes would sound like. I just read stuff on the web and I've read that the good ole NOS stuff sounds better than some of the Russian stuff.
I also used 2 watt Riken ohm stuff. For the 300B circuit, Joseph doubled up resistors to make 68.5 k ohms and 23.5 k ohms around the driver. I used 1 watt stuff there since they make 2 watts in parallel (besides being smaller and more easily fitted).
I read that using larger wattage resistors decreased the noise that it would make. There was a write up on the web, I forget who, but basically stated that use the quietest resistors in the driver section and use the carbons (if you want to) in the output tube section to add the "sound". I can definitely hear the difference in clarity between my SS amp and the 300B. I built the 300B for the sound and not to mimick the SS amp, or I wouldn't have built it at all.
I may experiment with WW or metal foil resistors later to see how they change the sound, but as for now, the amp sounds great.
I'm using Sylvania chrome top "Baldwin Organ" 6SN7GTB's. Sounds good. But being a newbie, I can't really say what other tubes would sound like. I just read stuff on the web and I've read that the good ole NOS stuff sounds better than some of the Russian stuff.
I also used 2 watt Riken ohm stuff. For the 300B circuit, Joseph doubled up resistors to make 68.5 k ohms and 23.5 k ohms around the driver. I used 1 watt stuff there since they make 2 watts in parallel (besides being smaller and more easily fitted).
I read that using larger wattage resistors decreased the noise that it would make. There was a write up on the web, I forget who, but basically stated that use the quietest resistors in the driver section and use the carbons (if you want to) in the output tube section to add the "sound". I can definitely hear the difference in clarity between my SS amp and the 300B. I built the 300B for the sound and not to mimick the SS amp, or I wouldn't have built it at all.
I may experiment with WW or metal foil resistors later to see how they change the sound, but as for now, the amp sounds great.
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