I am in the process of finishing up my FR horns, and with there high sensitivity and the small room they will be in I deff want to go with a flea watt SET.
2 watts should be good, which lead me to the S.E.X kit, however, for $400 I have the feeling that I can do better.
I dont want to be paying the premium for an enclosure to be shipped twice, if not more, and the additional markups. I have seen the STA45 kit and understand that it can be converted into a SET, but the issue of paying for the enclosure still comes up.
Iv searched but most amps I come up with are PP and striving to get higher wattages out so they can less efficent speakers.
Any help would be appreciated.
thanks
-greg
2 watts should be good, which lead me to the S.E.X kit, however, for $400 I have the feeling that I can do better.
I dont want to be paying the premium for an enclosure to be shipped twice, if not more, and the additional markups. I have seen the STA45 kit and understand that it can be converted into a SET, but the issue of paying for the enclosure still comes up.
Iv searched but most amps I come up with are PP and striving to get higher wattages out so they can less efficent speakers.
Any help would be appreciated.
thanks
-greg
Here's a thread from another forum about a spud amp kit that might meet your needs:
Spud Amp Kit
The first few kits have just been made ready for shipment, I think a couple are not yet spoken for. I've neither heard nor seen one, and have no relationship to the designer.
Spud Amp Kit
The first few kits have just been made ready for shipment, I think a couple are not yet spoken for. I've neither heard nor seen one, and have no relationship to the designer.
The easiest way I know into GOOD flea power SE amps, at modest cost, is to copy the DECWARE SE84 signal topology.
Triode wired 6V6 family tubes are LINEAR and an inexpensive 5965 will serve well in the voltage gain role. FWIW, the 'AQ5 used in "El Cheapo" is a member of the 6V6 family.
Replicate the "El Cheapo" B+ supply using the smaller (50 VA) Triad N-68X isolation trafo. A choke rated for 125 mA. is all that's necessary, but the C354 may be the best available deal.
You get what you pay for in SE O/P trafos. "Bottom feeding" for this project is the Hammond 125ESE.
Triode wired 6V6 family tubes are LINEAR and an inexpensive 5965 will serve well in the voltage gain role. FWIW, the 'AQ5 used in "El Cheapo" is a member of the 6V6 family.
Replicate the "El Cheapo" B+ supply using the smaller (50 VA) Triad N-68X isolation trafo. A choke rated for 125 mA. is all that's necessary, but the C354 may be the best available deal.
You get what you pay for in SE O/P trafos. "Bottom feeding" for this project is the Hammond 125ESE.
that looks alot like the kind of design im looking for, but I have a feeling that alot of that money is markup, as well as the drilled plate and all.
I have access to a metal shop as well as a wood working shop, so it seems like a pitty to spend money on things I can make without a problem.
thanks and I haev now added that into consideration. I might end up just going with a kit, but Im deff open to any other suggestions.
-greg
I have access to a metal shop as well as a wood working shop, so it seems like a pitty to spend money on things I can make without a problem.
thanks and I haev now added that into consideration. I might end up just going with a kit, but Im deff open to any other suggestions.
-greg
There are lots of options if you go DIY. Unfortunately the motherboard on my desktop seems to have fried. I have no links, no nothing on my laptop.
There's the amp in a tube ECL82 and 86.
If you want something swanker than the ECL8X and EL84 and if you can do with less than 1W, there's the 6F6 pentode, triode-strapped.
Here are some VT25/Type 10s for sale and a link to a schematic: http://cgi.ebay.com/1-Or-More-Tube-...ryZ50598QQrdZ1QQssPageNameZWD1VQQcmdZViewItem
Edit: "swank" being censored!?
There's the amp in a tube ECL82 and 86.
If you want something swanker than the ECL8X and EL84 and if you can do with less than 1W, there's the 6F6 pentode, triode-strapped.
Here are some VT25/Type 10s for sale and a link to a schematic: http://cgi.ebay.com/1-Or-More-Tube-...ryZ50598QQrdZ1QQssPageNameZWD1VQQcmdZViewItem
Edit: "swank" being censored!?
With some care and scrounging around you might manage a basic 2A3 dht amplifier for this sort of money. A pair of Sovtec 2A3 driven by a pair of 6SN7, along with a pair of transcendar 3K output transformers, hammond power transformer and choke plus a few passive parts and you will be at about budget.
I have a design I am not willing to share with the world at large just yet, however if you email me I will send you the details. It's upgradable - you can start with cheap passives as long as you have good iron and upgrade key parts as budget permits. It's very quiet as well.
Power output about 3Wrms, input sensitivity 2Vrms for full power.
Design uses SRPP direct coupled to output tube, and features psu ripple cancelling in output stage.
Email me through my website..
I have a design I am not willing to share with the world at large just yet, however if you email me I will send you the details. It's upgradable - you can start with cheap passives as long as you have good iron and upgrade key parts as budget permits. It's very quiet as well.
Power output about 3Wrms, input sensitivity 2Vrms for full power.
Design uses SRPP direct coupled to output tube, and features psu ripple cancelling in output stage.
Email me through my website..
Greg;
I have converted several of the STA45's to SET for freinds after they have listened to mine. I think it's a great deal.
As for the case, if you have the ability to build a speaker you can easily build a nice wood case for the amp.
Do you live close to Woodstock? If so do want to listen to one before you buy one?
tom
I have converted several of the STA45's to SET for freinds after they have listened to mine. I think it's a great deal.
As for the case, if you have the ability to build a speaker you can easily build a nice wood case for the amp.
Do you live close to Woodstock? If so do want to listen to one before you buy one?
tom
thanks for all the help guys. I will deff take you up in that Tom, if yyou really dont mind. Im about an hour away form you. Shoot me a email at gregmavity@gmail.com if you dont mind.
I'm also email you kevin to see what your design has to deal with.
thanks for the help guys. Im pretty new to tube design so alot of what your saying is kinda over my head, but im looking at it and tryign to read up on it so I understand what is going on.
-greg
I'm also email you kevin to see what your design has to deal with.
thanks for the help guys. Im pretty new to tube design so alot of what your saying is kinda over my head, but im looking at it and tryign to read up on it so I understand what is going on.
-greg
You have good flea amps at Magnequest, 45 and 2A3 tubes.
The tube 2A3 is cheap than the 45.
http://www.magnequest.com/diy2.htm
There are a forum too.
Best regards Jaime
The tube 2A3 is cheap than the 45.
http://www.magnequest.com/diy2.htm
There are a forum too.
Best regards Jaime
Diytube?
You may want to look at the latest project on DIYTUBE. They are preparing a circuit board design for a 6B4G SET amp. Look here... http://www.diytube.com/phpBB2/viewtopic.php?t=1369
You can do the chassis any way you want depending on how much you want to spend. You choose the transformers also.
I built two of the ST35 boards and they are very high quality and well documented. Sure simplifies the construction.
You may want to look at the latest project on DIYTUBE. They are preparing a circuit board design for a 6B4G SET amp. Look here... http://www.diytube.com/phpBB2/viewtopic.php?t=1369
You can do the chassis any way you want depending on how much you want to spend. You choose the transformers also.
I built two of the ST35 boards and they are very high quality and well documented. Sure simplifies the construction.
This is a great sounding little 2 watt SET based on the 6FD7 dual-dissimilar triode. Everyone that heard it seemed impressed 
http://geek.scorpiorising.ca/GeeK_ZonE/index.php?topic=1827.msg21728#msg21728
http://geek.scorpiorising.ca/GeeK_ZonE/index.php?topic=1827.msg21728#msg21728
I have been looking to build an EL84 SE amp. the main designs that I am looking at are the RH84 (google search), or the dc-coupled circuit by 'tubemaster'. the forum search doesn't seem to be picking the thread up at the moment, so here is a link.
Jaime, is that a 6c33c tube as your avatar?
James
Jaime, is that a 6c33c tube as your avatar?
James
For 2W there is no way to beat a 45 as far as I'm concerned. 2A3's are almost as good (really, can't go wrong with 2A3) and are cheaper.
If I were to build another 2A3 (or 45) amp I would build a monkey/free lunch/direct reactance drive. Look on Jeremy Epstein's page for s good discussion of the topology as well as a perfectly suitable circuit to build. http://home.earthlink.net/~jeremyepstein/freelunch.html
Also look at the Jack's DRD circuit on his Electra-Print site. http://www.electra-print.com/circuits.html His 2A3 circuit uses iron you can get from him. Not cheap but worth every penny. I would battery bias the input stage with a couple of 1.2V NiMH (see Jeremy's amp,) but that's just me...
-- Dave
If I were to build another 2A3 (or 45) amp I would build a monkey/free lunch/direct reactance drive. Look on Jeremy Epstein's page for s good discussion of the topology as well as a perfectly suitable circuit to build. http://home.earthlink.net/~jeremyepstein/freelunch.html
Also look at the Jack's DRD circuit on his Electra-Print site. http://www.electra-print.com/circuits.html His 2A3 circuit uses iron you can get from him. Not cheap but worth every penny. I would battery bias the input stage with a couple of 1.2V NiMH (see Jeremy's amp,) but that's just me...
-- Dave
I've been fiddling with a topology called STC (Super Triode Connection) where a triode is used as a feedback elemnt, thus giving the amplifier a triode characteristics (that's the theory at least ...).
I've built two such amps based on ECL82, will shortly set up an 807STC and have an EL84PP-STC "in the tube".
Much ideas and schematics can be found here: STC AMPS .
I can strongly recommend an experiment with the ECL82/6BM8, but using a pentode instead of the FET as input/CCS.
I've built two such amps based on ECL82, will shortly set up an 807STC and have an EL84PP-STC "in the tube".
Much ideas and schematics can be found here: STC AMPS .
I can strongly recommend an experiment with the ECL82/6BM8, but using a pentode instead of the FET as input/CCS.
Hi,
It all boils down to your intention of the project. Either its a learning experience or to buy your way to audio nivarna.
If it's for learning and comfident building, a SPUD single 6C45pi or 5842 can pump out ~1W per channel, yes, just one tube! The other good news is low-ish B+ of 90V to 160V you get to experiment with it, when you realised an amp is not just the tube, i.e. their is this PSU to play around, construction technique to learn, ground loop to deflate your morale, circuit layout to drive you insain and mechanical work to bleed, change operating point, tweak around with component sound, wires, delay power supply, voltage regulator....
Build head turning chassis... paint brush graphics...
When you are done with the single tube, and ego drive is high, you can add a bigger output stage (B+ of ~300V) such as 2A3 (2~3W), 45(1~1.6W), EL84 (6W pentode, 4W triode, UL strap...), EL34... etc etc, then you can play with coupling techniques begining with RC, then LC, interstage or CCS...
If you are brave enough, you can wind your own OPT... I wouldn't go that far...
When you think you are ready to conquar the world, grab a pair of 805 for 50W per channel and have fun with 2KV power supply...
It all depends on how much time and how eager are you to learn the hobby...
If you think that is too troublesome, you can always buy any kit that catch your liking live with it for ther rest of your lives...
Just my 2 cents
Safety first
Happy playing.
It all boils down to your intention of the project. Either its a learning experience or to buy your way to audio nivarna.
If it's for learning and comfident building, a SPUD single 6C45pi or 5842 can pump out ~1W per channel, yes, just one tube! The other good news is low-ish B+ of 90V to 160V you get to experiment with it, when you realised an amp is not just the tube, i.e. their is this PSU to play around, construction technique to learn, ground loop to deflate your morale, circuit layout to drive you insain and mechanical work to bleed, change operating point, tweak around with component sound, wires, delay power supply, voltage regulator....
Build head turning chassis... paint brush graphics...
When you are done with the single tube, and ego drive is high, you can add a bigger output stage (B+ of ~300V) such as 2A3 (2~3W), 45(1~1.6W), EL84 (6W pentode, 4W triode, UL strap...), EL34... etc etc, then you can play with coupling techniques begining with RC, then LC, interstage or CCS...
If you are brave enough, you can wind your own OPT... I wouldn't go that far...
When you think you are ready to conquar the world, grab a pair of 805 for 50W per channel and have fun with 2KV power supply...
It all depends on how much time and how eager are you to learn the hobby...
If you think that is too troublesome, you can always buy any kit that catch your liking live with it for ther rest of your lives...
Just my 2 cents
Safety first
Happy playing.
hi,
this is my first post in this thread.
Since I was not a full range user. But last month I was testing a small watts tubes amp for matching impendance of AKG K-1000.
( output 120Ohm). finaly I choose 6EM7 double triode witrh 3K OPT was very good. It will had around 1 Watts output. Triode sound. If U really like DHT, looks vt25 & vt52 was your cup of tea.
Some diyers will choose EL84 triode connect also a good choice but the sound field will not large, U can considerate EL504 triode connect.
thx
thomas
this is my first post in this thread.
Since I was not a full range user. But last month I was testing a small watts tubes amp for matching impendance of AKG K-1000.
( output 120Ohm). finaly I choose 6EM7 double triode witrh 3K OPT was very good. It will had around 1 Watts output. Triode sound. If U really like DHT, looks vt25 & vt52 was your cup of tea.
Some diyers will choose EL84 triode connect also a good choice but the sound field will not large, U can considerate EL504 triode connect.
thx
thomas
Audio Idiot:
So d@rn true. I'd say a simple SE-project with a nice and humble EL84 or 6V6 or any other user-friendly non-aggressive tube is a first project. There is no contradtiction between simple design and good sound quality, why a simple amp can be a good amp.
A 2A3 can be built very economical and simple and yet be a great piece in the battle for good music reproduction.
I'd also say, I have too many projects going on, but as I have gained some experience I'd for sure not hesitate to dig my teeth in a 845 or 211 or Russians like GM70 or GU72 (which is a DH pentode).
My recommendation to anyone is to either learn to walk at first or put on your blinds, close off your ears for any surrounding protests and build yourself a 400W OTL as your first project ...
So d@rn true. I'd say a simple SE-project with a nice and humble EL84 or 6V6 or any other user-friendly non-aggressive tube is a first project. There is no contradtiction between simple design and good sound quality, why a simple amp can be a good amp.
A 2A3 can be built very economical and simple and yet be a great piece in the battle for good music reproduction.
I'd also say, I have too many projects going on, but as I have gained some experience I'd for sure not hesitate to dig my teeth in a 845 or 211 or Russians like GM70 or GU72 (which is a DH pentode).
My recommendation to anyone is to either learn to walk at first or put on your blinds, close off your ears for any surrounding protests and build yourself a 400W OTL as your first project ...
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