Looks like there is. Even if there are openings at the bottom cover, the heat rises. That amp will appreciate the user by lasting longer if there are vents.
Agreed, but then that would greatly diminish the visual beauty of that beautiful wood grain.
It also appears he would only be using the smaller base tubes like EL34 as tubes like KT88 wouldn't fit in there.
My finished 300B
Well it was bit trying at times but i got my 300B working like I want it. Changed a couple of components around to lower B- from -230 to -154VDC. Added more heat sinking, a small fan for the 5 volt regulator. Small mV gauge to monitor the plates of the output tubes. All in all it was a good experience and the sound as you guys know is quite good. I added attenuators for volume and a output transformer impedance selector. Also added small heat sinks to B+ and B- output resistors.
Hammond 276X
One Electron UBT-3
Nichicon/Jensen and JJ Electrolytic's
Mundorf Couplers
Goldpoint Attenuators
Genelex Lions 300B,
Old School Raytheon Black Plate 5842
New Issue Mullard GZ34
Tell me what you guys think...
Well it was bit trying at times but i got my 300B working like I want it. Changed a couple of components around to lower B- from -230 to -154VDC. Added more heat sinking, a small fan for the 5 volt regulator. Small mV gauge to monitor the plates of the output tubes. All in all it was a good experience and the sound as you guys know is quite good. I added attenuators for volume and a output transformer impedance selector. Also added small heat sinks to B+ and B- output resistors.
Hammond 276X
One Electron UBT-3
Nichicon/Jensen and JJ Electrolytic's
Mundorf Couplers
Goldpoint Attenuators
Genelex Lions 300B,
Old School Raytheon Black Plate 5842
New Issue Mullard GZ34
Tell me what you guys think...
Attachments
Tubelab SSE Finished - I love it!
Power Transformer: EDCOR XPWR035
Output Transformers: EDCOR GXSE15-5K -6 Ohm
Choke: Hammond 159R
Motor Run Cap: 50 uF
Rectifier: Groove Tubes GT-5AR4
Electro-Harmonix 12AT7 EH Preamp Vacuum Tube
Electro-Harmonix EL34 EH Power Vacuum Tube
Switches for Ultra-Linear/Triode Mode and Cathode Feadback
The dial on the top is to switch the cathode resistor value
It's the first tube amp I own and my first electronics build of any kind ever.
Many thanks to George for designing an amp that just about anyone can make and all the contributors to this forum. I never even had to ask a question. It's all here.
This amp sounds fantastic! It's crystal clear with no hum or other noise. The sound is smooth and fluid, but still amazingly detailed.
Instruments are well separated with what seems like a 180 degree stage.
I prefer ultra-linear mode with cathode feedback.
It is more than loud enough for any room in my house, hooked up to my Klipsch Hersey IIIs or an old set of Polk 5 Jrs that I found at an antique store and a separate powered subwoofer.
The Herseys are 8 Ohm and the Polks are 4 Ohm. The 6 Ohm Opts seem to work well with both sets of speakers. I'm glad I went with the Edcors (that don't have the option of multiple secondaries, i.e. 4 Ohm and 8 Ohm), but do have the Ultra-linear tap because ultra-linear is what makes this amp really sound great to me.
I added a second set of RCA connectors to connect the subwoofer.
I removed the diodes from the board after I started blowing fuses after it played just fine for one full day. Then my original rectifier tube (Mullard) sparked out.
I also bought TubeDepot's octal base solid state rectifier as a back-up/cheap alternative for testing, which works fine by the way.
An externally hosted image should be here but it was not working when we last tested it.
Power Transformer: EDCOR XPWR035
Output Transformers: EDCOR GXSE15-5K -6 Ohm
Choke: Hammond 159R
Motor Run Cap: 50 uF
Rectifier: Groove Tubes GT-5AR4
Electro-Harmonix 12AT7 EH Preamp Vacuum Tube
Electro-Harmonix EL34 EH Power Vacuum Tube
Switches for Ultra-Linear/Triode Mode and Cathode Feadback
The dial on the top is to switch the cathode resistor value
It's the first tube amp I own and my first electronics build of any kind ever.
Many thanks to George for designing an amp that just about anyone can make and all the contributors to this forum. I never even had to ask a question. It's all here.
This amp sounds fantastic! It's crystal clear with no hum or other noise. The sound is smooth and fluid, but still amazingly detailed.
Instruments are well separated with what seems like a 180 degree stage.
I prefer ultra-linear mode with cathode feedback.
It is more than loud enough for any room in my house, hooked up to my Klipsch Hersey IIIs or an old set of Polk 5 Jrs that I found at an antique store and a separate powered subwoofer.
The Herseys are 8 Ohm and the Polks are 4 Ohm. The 6 Ohm Opts seem to work well with both sets of speakers. I'm glad I went with the Edcors (that don't have the option of multiple secondaries, i.e. 4 Ohm and 8 Ohm), but do have the Ultra-linear tap because ultra-linear is what makes this amp really sound great to me.
I added a second set of RCA connectors to connect the subwoofer.
I removed the diodes from the board after I started blowing fuses after it played just fine for one full day. Then my original rectifier tube (Mullard) sparked out.
I also bought TubeDepot's octal base solid state rectifier as a back-up/cheap alternative for testing, which works fine by the way.
seeing the tubes
I am building the Tubelab SE. I want to build it so the tube stick up out of the enclosure top. The problem is with all the components installed on the top of the board not all of the (or even most of the tubes) will extend above the enclosure top. If you look at George's pix of the plexiglass chassis you can see that the small tubes just show their tops. I would like all tube to stick out further.
First thought of mounting tube sockets on enclosure top with hard wire to PCB. Does anyone have opinion on that approach.
Also thought about mounting some larger parts on the bottom of the board leaving the board to be placed closer to the enclosure top.
I don't want to leave the board exposed as I have seen in some pictures. Looks nice but probably would kill my cat.
Any opinions?
I am building the Tubelab SE. I want to build it so the tube stick up out of the enclosure top. The problem is with all the components installed on the top of the board not all of the (or even most of the tubes) will extend above the enclosure top. If you look at George's pix of the plexiglass chassis you can see that the small tubes just show their tops. I would like all tube to stick out further.
First thought of mounting tube sockets on enclosure top with hard wire to PCB. Does anyone have opinion on that approach.
Also thought about mounting some larger parts on the bottom of the board leaving the board to be placed closer to the enclosure top.
I don't want to leave the board exposed as I have seen in some pictures. Looks nice but probably would kill my cat.
Any opinions?
winggo,
I think the following item will help you get more elevation for the 5842 tubes in Georges TSE:
9 Pin Socket Saver
| TubeDepot.com
This will allow you to lower the board a bit to accommodate the heatsinks.
I think the following item will help you get more elevation for the 5842 tubes in Georges TSE:
9 Pin Socket Saver
| TubeDepot.com
This will allow you to lower the board a bit to accommodate the heatsinks.
Another SE up and running!
The Tubelab SE by dcmeigs1
Here is the SE (on the right obviously) built out with the $20 Edcore OTs. I'm running 45s now and I've got the Power tubes loaded by the OT iron from an 845 amp. I hear a noticable difference between the two transformer sets, mostly if not completely, in the lower ranges, bass guitar and percussion.
The object is to replace the 845 front end (which sounds abhorent and looks even worse on a scope) with the TubleLab SE. The next step is to load the 45s with a constant current source and run the 45 plate signal to the 845 grid. The final step is to apply the Power Drive mosfet circuit to that signal as described in George's writing on the subject.
That 845 is a "Mr. Liang Audio" Chinese product. If you can find one at a salvage price, it has decent iron.
The TubeLab SE really sounds good at this stage. Probably the best sounding amp in the herd. It's suprising what a few watts can do. One could be forgiven for declaring victory now.
The Tubelab SE by dcmeigs1Here is the SE (on the right obviously) built out with the $20 Edcore OTs. I'm running 45s now and I've got the Power tubes loaded by the OT iron from an 845 amp. I hear a noticable difference between the two transformer sets, mostly if not completely, in the lower ranges, bass guitar and percussion.
The object is to replace the 845 front end (which sounds abhorent and looks even worse on a scope) with the TubleLab SE. The next step is to load the 45s with a constant current source and run the 45 plate signal to the 845 grid. The final step is to apply the Power Drive mosfet circuit to that signal as described in George's writing on the subject.
That 845 is a "Mr. Liang Audio" Chinese product. If you can find one at a salvage price, it has decent iron.
The TubeLab SE really sounds good at this stage. Probably the best sounding amp in the herd. It's suprising what a few watts can do. One could be forgiven for declaring victory now.
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You can mount the semiconductors on the bottom of the board, many of us here have done it.......grab the board and a mosfet or CCS and think about it a bit....
What I've done is mark the lead that is next to the dot on the front side of the board with a marker and then I make sure that is the one next to the dot when I insert it from the other side.
I can get the heat sinks to work on the other side of the board by bending the leads. I've built three boards this way.
Hope that makes sense.
Good luck,
I have the caps on the bottom and the rest on top. Using socket savers on the 5842's and the rectifier just to get a nice lift.
So many options to build this board but heat is an enemy in some builds so just keep that in mind.
