Well, as I find myself sitting half way across the world in a desert on deployment, I decided that I'll need to treat myself to a 300B amplifier setup when I get to return back home. I would like to build it myself (I've built 2 of Doc Bottlehead's foreplay preamps so far). There just seem to be so many choices, I am not sure where to go. Doc Bottlehead has his own 300B monoblock kits, at $1500 without tubes. I've seen a few others on various websites. A commonly talked one is the JE Labs 300B schematic on Angela. Seems simple enough to put together, but in terms of parts I am lost. It seems I could spend anywhere from $50 on handmade transformers to over $500 on exotic ones. Without having a way to listen to the different ones, I am hoping for help. I don't have the money to do a bunch of swaps to figure out what I want, but if I can do perfectly fine with the $50 handmades, and maybe a few years later upgrade, I will. Same goes for caps / resistors. I guess that would be part of the fun in finding out which swaps to higher grade components yield the most gain in how good the amps sound. Last, I am not capable of making my own chassis plates (at least I don't think I am). Any suggestions where to get the chassis prepunched? Thanks again for everyone's help.
Mark
Mark
How about...
http://gabevee.tripod.com/cgv300b.html ?
Inexpensive, simple, great sounding, priced with tubes and high quality One Electron transformers!
Just read customer comments. Also, unit now looks much better than the one in the picture. New picture coming soon.
Gabe
http://gabevee.tripod.com/cgv300b.html ?
Inexpensive, simple, great sounding, priced with tubes and high quality One Electron transformers!
Just read customer comments. Also, unit now looks much better than the one in the picture. New picture coming soon.
Gabe
Joel: I am not going to apologize for having internet access where I am. On occasion, we have a chance to get online to send email to love ones, or to browse as a means to decompress. Personally I think about audio or building something to do with audio to relax. You are certainly entitled to your opinion that that is a waste of your tax money, and I will defend your right to that opinion to the death. Whether or not you agree with what the military is doing right now is another matter. But believe me, I did not choose to leave my wife for an unknown amount of time. I also do not feel bad having a way to assure her that I am still alive.
Thank you Robert.
Actually, we do. It is the best way for soldiers to be able to communicate with their loved ones to let them know they are ok. Regular mail takes roughly 3-4 weeks, while email is almost instantantaneous.
With that said, any other comments on my original question of places to look at for kits or plans for 300B monoblocks or stereo amps? Thanks.
Mark
Robert Morin said:
YES!(I think)
Is his life on the line to have a free country for you to surf the net from?YES
Robert Morin
Thank you Robert.
Joel said:I doubt they have combat zone internet access... but anyway.... what was the question?
Actually, we do. It is the best way for soldiers to be able to communicate with their loved ones to let them know they are ok. Regular mail takes roughly 3-4 weeks, while email is almost instantantaneous.
With that said, any other comments on my original question of places to look at for kits or plans for 300B monoblocks or stereo amps? Thanks.
Mark
Mach_Y
First of all a hearty thank you for putting your life on the life in order to safeguard our freedom that we prize so highly.
You are certainly due some leasure time and it pleases me that you also share the zest for the audio bug.
Just my .02 here.... I would have to recommend that you contact Gabe. This is based on the good feedback I have received from friends. I haven't personally had the priviledge of seeing his product but others seem to be very satisfied.
Take care!
Joe
First of all a hearty thank you for putting your life on the life in order to safeguard our freedom that we prize so highly.
You are certainly due some leasure time and it pleases me that you also share the zest for the audio bug.
Just my .02 here.... I would have to recommend that you contact Gabe. This is based on the good feedback I have received from friends. I haven't personally had the priviledge of seeing his product but others seem to be very satisfied.
Take care!
Joe
I can attest to Gabevee's product. I built one of his kits, and a schematic off his web site. I am in the process of building his 2A3 design which is in another thread in this forumn. If, by chance, you decide to go it alone let me know. I will help you any way I can, even punching out your chassis for you. Keep your head down and God Bless You and Your Family.
SYMPATHY ALL OVER.
Hi,
From what I see, most of the SE designs suffer from whimpy PSU designs.
FWIW, a simple test done amongst friends showed that any SE design approaches PP bass slam when it was given a well designed PSU.
Tests were done with highly efficient speakers, so efficient that, indeed, you wouldn't think it'd make a difference.
If you can, make driver and output PSU as independent from each other as possible and enjoy real IDHT sound.
Not that I'm such a big fan of SETs but the idea is worth pursuing in any topology really.
My 2 cents and a big heart to all US soldiers involved in Vietnam II,
Hi,
From what I see, most of the SE designs suffer from whimpy PSU designs.
FWIW, a simple test done amongst friends showed that any SE design approaches PP bass slam when it was given a well designed PSU.
Tests were done with highly efficient speakers, so efficient that, indeed, you wouldn't think it'd make a difference.
If you can, make driver and output PSU as independent from each other as possible and enjoy real IDHT sound.
Not that I'm such a big fan of SETs but the idea is worth pursuing in any topology really.
My 2 cents and a big heart to all US soldiers involved in Vietnam II,
Re: SYMPATHY ALL OVER.
Joe, thank you for the kind words, they are greatly appreciated.
It is good to see so many speaking highly of Gabevee's product. That is certainly a good sign. I am looking at that and the Angela RE Labs 300B amp design. I added up the cost of the "suggested" parts from angela, and minus tubes and chassis, the total will be over $900 with shipping. If the design and parts are truly worth the amount of money, I am willing to go that route.
Your offer of help and labor are greatly appreciated. The help I'd take for free, but I wouldn't allow you to work on a chassis for me without accepting payment.
That is definitly something to think about. In other projects I have worked on (solid state) power supply does make a huge difference, and I don't see why the same wouldn't apply to SET's. I am not sure what you would consider to be a "well designed PSU". Are you referring to using enough filters so that ripple is not measurable? or perhaps making sure the tranny is capable a producing well over the amount being asked of it? or having an increase in the amount of capacitance? or maybe replacing a vacuum tube power supply with a solid state power supply using ultra fast soft recovery diodes? If the idea is to create as solid of a voltage as possible that is needed for the circuit, there are many routes to go. Could you reply as to what powe supplies you tried in your experiment? This might be a good route to take if making a "high end" power supply would help. Possibly could look into the solid state or pass labs forum and glean information into what they are using. As a good example, the pass zen line are pretty much the solid state equivelent of SET. Maybe using the pass zen power supply topology would be a good route to take?
Thanks again everyone for the great comments
burnedfingers said:Mach_Y
First of all a hearty thank you for putting your life on the life in order to safeguard our freedom that we prize so highly.
You are certainly due some leasure time and it pleases me that you also share the zest for the audio bug.
Just my .02 here.... I would have to recommend that you contact Gabe. This is based on the good feedback I have received from friends. I haven't personally had the priviledge of seeing his product but others seem to be very satisfied.
Take care!
Joe
Joe, thank you for the kind words, they are greatly appreciated.
PassFan said:I can attest to Gabevee's product. I built one of his kits, and a schematic off his web site. I am in the process of building his 2A3 design which is in another thread in this forumn. If, by chance, you decide to go it alone let me know. I will help you any way I can, even punching out your chassis for you. Keep your head down and God Bless You and Your Family.
It is good to see so many speaking highly of Gabevee's product. That is certainly a good sign. I am looking at that and the Angela RE Labs 300B amp design. I added up the cost of the "suggested" parts from angela, and minus tubes and chassis, the total will be over $900 with shipping. If the design and parts are truly worth the amount of money, I am willing to go that route.
Your offer of help and labor are greatly appreciated. The help I'd take for free, but I wouldn't allow you to work on a chassis for me without accepting payment.
fdegrove said:Hi,
From what I see, most of the SE designs suffer from whimpy PSU designs.
FWIW, a simple test done amongst friends showed that any SE design approaches PP bass slam when it was given a well designed PSU.
Tests were done with highly efficient speakers, so efficient that, indeed, you wouldn't think it'd make a difference.
If you can, make driver and output PSU as independent from each other as possible and enjoy real IDHT sound.
Not that I'm such a big fan of SETs but the idea is worth pursuing in any topology really.
My 2 cents and a big heart to all US soldiers involved in Vietnam II,
That is definitly something to think about. In other projects I have worked on (solid state) power supply does make a huge difference, and I don't see why the same wouldn't apply to SET's. I am not sure what you would consider to be a "well designed PSU". Are you referring to using enough filters so that ripple is not measurable? or perhaps making sure the tranny is capable a producing well over the amount being asked of it? or having an increase in the amount of capacitance? or maybe replacing a vacuum tube power supply with a solid state power supply using ultra fast soft recovery diodes? If the idea is to create as solid of a voltage as possible that is needed for the circuit, there are many routes to go. Could you reply as to what powe supplies you tried in your experiment? This might be a good route to take if making a "high end" power supply would help. Possibly could look into the solid state or pass labs forum and glean information into what they are using. As a good example, the pass zen line are pretty much the solid state equivelent of SET. Maybe using the pass zen power supply topology would be a good route to take?
Thanks again everyone for the great comments
hi mike,
if simple & economic I will choose JE labs.
That's good.
If averiable of budget I will choose transformer couple, I use 6C45 with 1:2 transformer couple to the 300B. Very simple ( Fit with DIY spirit---simple of the best). One channel with 10 pieces of components. I use advance signature series 89db speaker & test with cello & big drum about the controling power. Which compare with cary 211 se amp to get an objective result.
The result was only a little bit worse than the 211se in the controling & hear the size of the drum was large than the 211se amp. The more detail & pin point was 300b best.
Transformer couple 300b is much powerful than cap couple.
But the bandwidth of the interstage was very important.
I will post this amp tonight.
cheers
Thomas
if simple & economic I will choose JE labs.
That's good.
If averiable of budget I will choose transformer couple, I use 6C45 with 1:2 transformer couple to the 300B. Very simple ( Fit with DIY spirit---simple of the best). One channel with 10 pieces of components. I use advance signature series 89db speaker & test with cello & big drum about the controling power. Which compare with cary 211 se amp to get an objective result.
The result was only a little bit worse than the 211se in the controling & hear the size of the drum was large than the 211se amp. The more detail & pin point was 300b best.
Transformer couple 300b is much powerful than cap couple.
But the bandwidth of the interstage was very important.
I will post this amp tonight.
cheers
Thomas
Attachments
Point well taken Frank, I guess it is easy to try to forget the friends and comrades that didn't return with us because the hurt is still there. The war wasn't well received by the american people.
Mark
When you finish your tour and if your travels take you to the midwest contact me and I'll buy you the biggest beer you can drink. The offer is there also for any chassis work or help that I could provide. I have a shop full of electronic equipment also, testing would be a breeze.
God Speed
Joe
SET PSU.
Hi,
Mark,
You pretty much sum it up yourself here.
Audible improvements were obtained by:
Dedicated PSU for driver and output stages, added reservoir capacitance and better bass performance was had by replacing a tube rectifier for a solid state one using UF soft recovery diodes with a snubber network across them.
Not tried but generally good practice: a powerxformer with say 30 to 40% higher than calculated VA rating and an electrostatic shield, results will of course be depending on the built quality of the unit.
Low ripple on the B+ is of course a must.
I could go on and on but it seems you got the picture already so I'll leave you to your own experiments and welcome any feedback.
Talking about feedback, use local feedback iso global loops if you must use it at all.
Cheers,
Hi,
Mark,
You pretty much sum it up yourself here.
Audible improvements were obtained by:
Dedicated PSU for driver and output stages, added reservoir capacitance and better bass performance was had by replacing a tube rectifier for a solid state one using UF soft recovery diodes with a snubber network across them.
Not tried but generally good practice: a powerxformer with say 30 to 40% higher than calculated VA rating and an electrostatic shield, results will of course be depending on the built quality of the unit.
Low ripple on the B+ is of course a must.
I could go on and on but it seems you got the picture already so I'll leave you to your own experiments and welcome any feedback.
Talking about feedback, use local feedback iso global loops if you must use it at all.
Cheers,
Hi Mach_Y;
Thanks from everyone here in the states for your sacrifices and the job you guys are doing! The prayers of everyone here are with you and all the other members of the US and Coalition forces!!
Okay, on to audio.
Which 300B? I'm no expert, but I have built the JE Labs 2A3, which is very similar to their 300B design. I almost went with their 300B, but the cost of stocking spare 300B's was disheartening. The 2A3 'version' is a good sounding amp, and the trickiest bit was the chassis fabrication.
The design by GabeVee looks good too, though I've not built it.
As far as 'which transformers', the Hammond 1627SE are just fine (and they're the the same trafos that I would have used had I built it as a 300B). They have good treble, unbelievably smooth midrange, and the bass can surprise you (limited by the 4 watts of output power). I've seen some positive opinions posted about the less pricey Hammond 125ESE, but I can't give you a first hand comment on them. DO NOT feel like you need to spring for the priciest Japanese iron to get good results (nothing against them, but ye gods the price!).
Definitely DO overbuild your power supply for the best sound - and you might consider one of Hammond's 37XX series. They can be wired for different AC mains voltages (so you could make a 'universal' amp for which all you would need to do would be to throw a switch internally to change it over for different country's power grids).
IMHO the most important 'little' expense would be to go with good quality carbon film or carbon comp resistors as the load resistors for the input valves. Don't forget good coupling caps too!! If money's an issue, the Sprague 716P Orange Drop is a nice sounding cap (and only $2 each!).
You can find pics of my 2A3 at http://home.earthlink.net/~shidenkai/index.html
Good luck and all the best!!
Morse
Thanks from everyone here in the states for your sacrifices and the job you guys are doing!
The prayers of everyone here are with you and all the other members of the US and Coalition forces!! Okay, on to audio.
Which 300B? I'm no expert, but I have built the JE Labs 2A3, which is very similar to their 300B design. I almost went with their 300B, but the cost of stocking spare 300B's was disheartening. The 2A3 'version' is a good sounding amp, and the trickiest bit was the chassis fabrication.
The design by GabeVee looks good too, though I've not built it.
As far as 'which transformers', the Hammond 1627SE are just fine (and they're the the same trafos that I would have used had I built it as a 300B). They have good treble, unbelievably smooth midrange, and the bass can surprise you (limited by the 4 watts of output power). I've seen some positive opinions posted about the less pricey Hammond 125ESE, but I can't give you a first hand comment on them. DO NOT feel like you need to spring for the priciest Japanese iron to get good results (nothing against them, but ye gods the price!).
Definitely DO overbuild your power supply for the best sound - and you might consider one of Hammond's 37XX series. They can be wired for different AC mains voltages (so you could make a 'universal' amp for which all you would need to do would be to throw a switch internally to change it over for different country's power grids).
IMHO the most important 'little' expense would be to go with good quality carbon film or carbon comp resistors as the load resistors for the input valves. Don't forget good coupling caps too!! If money's an issue, the Sprague 716P Orange Drop is a nice sounding cap (and only $2 each!).
You can find pics of my 2A3 at http://home.earthlink.net/~shidenkai/index.html
Good luck and all the best!!
Morse
HI Mach_Y,
AS THEY SAID the transformer couple circuit.
All type of the transformer were good for the circuit.
All diyer hope to find ther best p/c ratio one.
the Hammond 1627SE also the best but this worild never will had free lunch.
The cheaperest tran I use with choke is james. best is tango & tamura.
U can try to check the je labs web to see the opinion.
At last they choose to use is Tamura f5002 & tango NY-15-3.5S.
Certainly, they were very expensive. But I choose james or tango xe20s will had three set of primary 2.5k, 35K & 5K. U can use different to tune the sound quality.
For example the 5K is less disortion than 3.5K but will less power output.
For U to turn the sound will increase the flexible.
Secondary is Later U can choose another tubes 6l6,el34 kt88 SE to use but not need to exchange the opt.
pls click,
this JE lab website.
http://users.starpower.net/je2a3/Gallery.htm
U can see the end opt choose is tamura f5002 & tango ny-15-3.5S.
Pls see the kit I pre pare to Use is brand new one in tango iso xe20s.
thanks
Thomas
AS THEY SAID the transformer couple circuit.
All type of the transformer were good for the circuit.
All diyer hope to find ther best p/c ratio one.
the Hammond 1627SE also the best but this worild never will had free lunch.
The cheaperest tran I use with choke is james. best is tango & tamura.
U can try to check the je labs web to see the opinion.
At last they choose to use is Tamura f5002 & tango NY-15-3.5S.
Certainly, they were very expensive. But I choose james or tango xe20s will had three set of primary 2.5k, 35K & 5K. U can use different to tune the sound quality.
For example the 5K is less disortion than 3.5K but will less power output.
For U to turn the sound will increase the flexible.
Secondary is Later U can choose another tubes 6l6,el34 kt88 SE to use but not need to exchange the opt.
pls click,
this JE lab website.
http://users.starpower.net/je2a3/Gallery.htm
U can see the end opt choose is tamura f5002 & tango ny-15-3.5S.
Pls see the kit I pre pare to Use is brand new one in tango iso xe20s.
thanks
Thomas
Attachments
my another transformer couple 300b will use this circuit.
http://www.tubebuilder.com/images/schematics/singleended/we300b_se4.gif
I test this circuit is very good. WE437a can USE 6C45.
but the transformer I choose tango iso NC16 & james or tango xe20s. Depends on the buyer's budget.
Pls see the NC16.
thanks
Thomas
http://www.tubebuilder.com/images/schematics/singleended/we300b_se4.gif
I test this circuit is very good. WE437a can USE 6C45.
but the transformer I choose tango iso NC16 & james or tango xe20s. Depends on the buyer's budget.
Pls see the NC16.
thanks
Thomas
Attachments
thank you everyone for the kind words. They mean so much while over here. If I ever am out midwest, I might just come find you for that beer btw!
Anyway, looks like I have some homework to do on the upgraded / outboard power supply. Might be a interesting project.
Thomas... you keep showing pictures of great looking transformers and all, but never any prices. Please, either post prices or respond to the numerous emails I have sent you. Thanks!
So either the JE Labs or Gabavee's.... hrmm... decisions... decisions....
Anyway, looks like I have some homework to do on the upgraded / outboard power supply. Might be a interesting project.
Thomas... you keep showing pictures of great looking transformers and all, but never any prices. Please, either post prices or respond to the numerous emails I have sent you. Thanks!
So either the JE Labs or Gabavee's.... hrmm... decisions... decisions....
hi, why not go to my www.diyaudiocraft.com
to cheap.
Tango XE20S USD 420 pair.
James JS 6123HS USD 200 pair.
Tango NC14 1:1 ,NC16 1:2 interstage cost USD 255 per pair.
is it reasonable.
This is the best I can do.
Hope this will be the another choice to the foreign diyer.
thanks
Thomas
to cheap.
Tango XE20S USD 420 pair.
James JS 6123HS USD 200 pair.
Tango NC14 1:1 ,NC16 1:2 interstage cost USD 255 per pair.
is it reasonable.
This is the best I can do.
Hope this will be the another choice to the foreign diyer.
thanks
Thomas
After trying a few 300B SE circuits, I settled on one circuit, that I feel can outdo everyone, its the Direct Reactance Drive amp by Jack Elliano of Electra-Print, here is the website:
http://my.execpc.com/~n9zes/drd300b.html
The circuit published in Vacuum Tube Valley Magazine uses solid state rectifier for the PSU, I have built both and they both are ok. This amp is so simple and yet will give the level of detail that no other amp can give. I think this is due to the fact that there is no coupling cap in the signal cap, the choke loaded driver tube and the big Oil cap connected at the B+ and Cathode of the 300B. Be prepared though as the clarity of this amp is so high that it will reveal not only detail but unpleasant discrepancies from your sources as well.
Let me know if you decide to do this and I can give you more tips on building this.
Alex
http://my.execpc.com/~n9zes/drd300b.html
The circuit published in Vacuum Tube Valley Magazine uses solid state rectifier for the PSU, I have built both and they both are ok. This amp is so simple and yet will give the level of detail that no other amp can give. I think this is due to the fact that there is no coupling cap in the signal cap, the choke loaded driver tube and the big Oil cap connected at the B+ and Cathode of the 300B. Be prepared though as the clarity of this amp is so high that it will reveal not only detail but unpleasant discrepancies from your sources as well.
Let me know if you decide to do this and I can give you more tips on building this.
Alex
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