I have been given permission to spend a little money on a tube amp for my office at work.
Now, I do not have much to spend at all. It seems that the Tube Lab SimpleSe could be very inexpensive and can output around 10WPC.
Of course, I do not have speakers for my office and was thinking cheap and bookshelf.
Anyway, we recently put some Sony 2-way bookshelf speakers in the baby's room. He likes them and they are around $50 a pair.
Now with a 10W SimpleSE powered by iTunes via the audio jack, going into 87dB speakers, will I hear anything?
Otherwise, can anyone recommend sub $100 higher efficiency speakers.
Charlie
Now, I do not have much to spend at all. It seems that the Tube Lab SimpleSe could be very inexpensive and can output around 10WPC.
Of course, I do not have speakers for my office and was thinking cheap and bookshelf.
Anyway, we recently put some Sony 2-way bookshelf speakers in the baby's room. He likes them and they are around $50 a pair.
Now with a 10W SimpleSE powered by iTunes via the audio jack, going into 87dB speakers, will I hear anything?
Otherwise, can anyone recommend sub $100 higher efficiency speakers.
Charlie
Without the "bells and whistles", this amp would be cheap to build. I guess the big dollars would be saved by using budget output transformers and tubes. The extra filter cap and choke will only cost about $30 extra to include.
I have built this amp and absolutely love it. The design of the board and the detailed instructions on the TubeLab web site allowed me to build a very quiet (as in no hum) sweet sounding amp without really knowing much of the "tricks of the trade" in tube amp construction. I am running the budget Edcor XSE15-8-5K transformers and have found them quite good (I have active crossover and stereo bass units for <80Hz). I am running JJ ECC81 input tube and JJ E34L output tubes. I have also got some JJ KT88 tubes. After several weeks of listening, I have found that I prefer the E34Ls to the KT88s. In my setup the E34Ls sound a little more detailed. The KT88s sound louder in the bass, but in my setup and in my opinion, the bass sounds a little muddier and the highs slightly less detailed. The E34Ls also cost significantly less and offer slightly more output power in this setup.
I might add that I think that this amp would be wasted on an MP3 system, but I am biased, I love mine in my main system.
Another thing that may be worth investigating, audio pre-amps and CD players etc should not have any DC offset in their output but I am not quite so sure about MP3 players and computer soundcards. It might be worth asking some of the more knowledgeable members of this forum if they would recommend adding a capacitor to the input of the amp to protect from DC. I am currently building a little 6BM8/ECL82 push pull amp for my girlfriend ( http://www.bonavolta.ch/hobby/en/audio/ecl82_2.htm ) for exactly the same purpose you are building yours and have decided to add a capacitor to the input just in case her iPod or computer has some DC (this was on the recommendation of my father, an electronics engineer).
If you do decide to build this amp please leave some feedback for the forum and for TubeLab. I think George has sold a few of the boards but have not seen much feedback on the forum or on his site.
Cheers,
Chris
I have built this amp and absolutely love it. The design of the board and the detailed instructions on the TubeLab web site allowed me to build a very quiet (as in no hum) sweet sounding amp without really knowing much of the "tricks of the trade" in tube amp construction. I am running the budget Edcor XSE15-8-5K transformers and have found them quite good (I have active crossover and stereo bass units for <80Hz). I am running JJ ECC81 input tube and JJ E34L output tubes. I have also got some JJ KT88 tubes. After several weeks of listening, I have found that I prefer the E34Ls to the KT88s. In my setup the E34Ls sound a little more detailed. The KT88s sound louder in the bass, but in my setup and in my opinion, the bass sounds a little muddier and the highs slightly less detailed. The E34Ls also cost significantly less and offer slightly more output power in this setup.
I might add that I think that this amp would be wasted on an MP3 system, but I am biased, I love mine in my main system.
Another thing that may be worth investigating, audio pre-amps and CD players etc should not have any DC offset in their output but I am not quite so sure about MP3 players and computer soundcards. It might be worth asking some of the more knowledgeable members of this forum if they would recommend adding a capacitor to the input of the amp to protect from DC. I am currently building a little 6BM8/ECL82 push pull amp for my girlfriend ( http://www.bonavolta.ch/hobby/en/audio/ecl82_2.htm ) for exactly the same purpose you are building yours and have decided to add a capacitor to the input just in case her iPod or computer has some DC (this was on the recommendation of my father, an electronics engineer).
If you do decide to build this amp please leave some feedback for the forum and for TubeLab. I think George has sold a few of the boards but have not seen much feedback on the forum or on his site.
Cheers,
Chris
cbutterworth said:
Charlie,
In my family room system I have SE KT88 amps putting out about 7 watts. I am using Dynaco A25s in that setup and it goes plenty loud for me in that room. (Room is about 13 feet by 17 feet with an 8 foot ceiling and an 8 foot opening into the next room.) I don't know the efficiency of the Dynacos but I would guess no more than 89dB.
I've also used those same amps with Advent /1 speakers which are slightly less efficient and probably about the same as yours. I found that for almost all the music I listen to they were also quite loud enough.
In an office 10WPC would be plenty I think.
Great replies - Thanks!
I have just invested a chunk of change on a Cornet2 phono-pre from Jim Hagerman. I used premium parts for signal caps, etc., so the cost was quite substantial ($400 - $500), but it's worth it. I expect that my Aikido pre cost a similar amount, although I am less sure, it may have cost quite a bit less.
Having had six months of vacuum tubes in my system, I have decided that I love them. My main amp is a 55W solid state AKSA 55N. This is supposed to be a very high quality amp and has a solid DIY following. This, coupled with lack of space means that a vacuum-tubed main amp for my home system is out of the question. Hence one for my office.
When I mentioned this to my wife, I was expecting a "go shove it" instead, I got a "go for it"
I have always planned for some music in my office. As a scientist, I need to keep myself well-read on current articles. I already have a comfy reading chair, and the thought of some nice sounding music should really inspire me to spend a hour each day catching up on the latest.
Anyway, $200-300 on an amp and up to $100 for speakers could be justified. Maybe if the SimpleSE sounds really good, I'll be allowed to keep it at home and invent a way of adding it to my home system alongside my solid-sate power amp (to which I feel some loyality).
Yes, I could build some speakers, if less than $100.
Regards,
Charlie
I have just invested a chunk of change on a Cornet2 phono-pre from Jim Hagerman. I used premium parts for signal caps, etc., so the cost was quite substantial ($400 - $500), but it's worth it. I expect that my Aikido pre cost a similar amount, although I am less sure, it may have cost quite a bit less.
Having had six months of vacuum tubes in my system, I have decided that I love them. My main amp is a 55W solid state AKSA 55N. This is supposed to be a very high quality amp and has a solid DIY following. This, coupled with lack of space means that a vacuum-tubed main amp for my home system is out of the question. Hence one for my office.
When I mentioned this to my wife, I was expecting a "go shove it" instead, I got a "go for it"
I have always planned for some music in my office. As a scientist, I need to keep myself well-read on current articles. I already have a comfy reading chair, and the thought of some nice sounding music should really inspire me to spend a hour each day catching up on the latest.
Anyway, $200-300 on an amp and up to $100 for speakers could be justified. Maybe if the SimpleSE sounds really good, I'll be allowed to keep it at home and invent a way of adding it to my home system alongside my solid-sate power amp (to which I feel some loyality).
Yes, I could build some speakers, if less than $100.
Regards,
Charlie
The SimpleSE and all of my amplifiers were developed and tested with 87db Yamaha NS-10M studio monitors. These are not the most tube friendly speakers in the world. The volume level in my 10 X 11 foot lab is loud. Not extremely loud, but loud. Loud enough to annoy Sherri in the other end of the house with the doors closed. I can't imagine an office where this setup wouldn't generate enough sound. I routinely listen to a TubelabSE with 45's or a low powered SimpleSE with trioded 6V6's through these speakers. Both amps make about 1.5 watts. This is not loud, but adequate for comfortable listening.
I am now using an EMU 1212 24 bit 192 KHz sound card for most of my music playing. It works great. I have also used a M-audio Audiophile 2496 card. I am slowly ripping my entire CD collection to disc using exact audio copy. The sound is better than my CD player. I have no experience with MP3 players. Many SS amps really hate DC offset, so I imagine any "line output" should be OK. Some headphone outputs may have a small offset without a headphone load, but a few millivolts won't bother the SimpleSE.
Chris: I have sold about 60 boards total. Several people have emailed me saying that they have finished their amps, but you are the only person to send pictures of a completed amp. I recently got a picture of a board fired up and working (trioded 6V6 again), but haven't had time to post it yet.
I am now using an EMU 1212 24 bit 192 KHz sound card for most of my music playing. It works great. I have also used a M-audio Audiophile 2496 card. I am slowly ripping my entire CD collection to disc using exact audio copy. The sound is better than my CD player. I have no experience with MP3 players. Many SS amps really hate DC offset, so I imagine any "line output" should be OK. Some headphone outputs may have a small offset without a headphone load, but a few millivolts won't bother the SimpleSE.
Chris: I have sold about 60 boards total. Several people have emailed me saying that they have finished their amps, but you are the only person to send pictures of a completed amp. I recently got a picture of a board fired up and working (trioded 6V6 again), but haven't had time to post it yet.
Blank PC boards are $35 and shipping is $8 in the US. You do not have the email feature enabled through this forum, so I can't send you email. Email me and I will forward you the ordering info. My email address is at the bottom of my home page, and I am attempting to include it here.
Never put your email address in text format in a public forum. The evil spam robots will find it and bomb your email box with junk.
Never put your email address in text format in a public forum. The evil spam robots will find it and bomb your email box with junk.
Attachments
arnoldc said:
1st small & efficient don't really go together, the formula for speaker efficiency has the cone area as a term.
If looking at new drivers...
1st to consider would be a small FE127e speaker. We are working on a 4.5 litre one right now. We have done 2 iterations and have a 3rd in concept. This one would strain the $100 budget by the time shipping & taxes are added (and that is for stock drivers from Madisound). And that is before wood is considered -- but they don't take much. To save a few bucks FE103 would be next. The Solo 103 would be worth looking at). Even smaller i'm working on a 2 litre FF85 box. These is going to reach much below 100 hz, but are capable of being excellent everywhere else.
If you know what to look for, and get a bit lucky, some really decent thrift store finds are about... one level higher is buying on eBay from someone who has already sifted thru the thrift stores (even then the work to sell some decent frugal-phile(tm) drivers is greater than the return (i just gave away about 900 pounds of drivers because it would have cost more to list them than i'd get in return -- and i needed the room)
dave
The board is stereo with the power supply circuitry. Look at the assembly manual, and amplifier build ups for the two high powered amps, on the web site.
I personally have three SimpleSE's:
The low power amp uses 6V6 tubes in triode mode, an Allied 6K56VG power transformer, and Edcor XSE15-8-5K OPT's. This began as an experiment to verify the combination, but sounds so nice that I can't part with it. It makes about 1.5 watts.
The high powered amps use EL34's or KT88's or even 6L6GC's. I use an Allied 6K7VG power transformer. And an OPT with a 5K ohm primary impedance.
My industrial amp currently uses Transcendar 3K ohm OPT's made for 300B use (Ebay). I am running my 8 ohm speakers on the 4 ohm taps for a 6 K ohm load. These transformers do NOT have the UL tap so ultralinear operation is not available. This amp makes 6 to 8 watts in triode mode.
I have another SimpleSE that uses Hammond 1628SEA's. These transformers have the best bass by far since they are huge by comparison (11 pounds). The response is a bit weak in the upper highs (above 15 KHz) and they are over $100 each. In UL mode I get 10 to 14 watts.
For a good low budget alternative use the Edcor XSE15-8-5K OPT's. They have raised the price on these guys to $19 each. If your speakers don't have much bass below 70 Hz (most small speakers) these are a good alternative to high priced transformers. They worked good with my Yamaha speakers that have a 7 inch woofer, but I opted for a bigger transformer for use with my 15 inch speakers in the living room.
Other OPT's with a 4.8 to 6 K ohm primary will work. I use the Allied 6K7VG power transformer (made by Hammond) because of its low cost $47. A Hammond 274BX will work, but it is essentially the same transformer for more money. Other 750 VCT @ 175 mA transformers will work too.
Another possibility is to go the conventional route and use a lower B+ voltage with a 2.5 to 3.6 K ohm transformer. I have built amps like these for others, but I prefer the dynamics of a higher voltage and a higher load impedance. If you want to try this, you need a power transformer that puts out 600 to 650 VCT at 175 mA with 5 and 6.3 volt windings. The Transcendar 300B OPT, a One Electron UBT-3, or a Hammond 1627SEA can be used. I used some surplus 650 VCT power transformers and Transcendar OPT's.
Assembly manual:
http://www.tubelab.com/AssemblyManualSimpleSE/StartHere_SSE.html
Industrial amp:
http://www.tubelab.com/Industrial1.htm
Fisher Cabinet amp:
http://www.tubelab.com/AssemblyManualSimpleSE/FisherCabinetAmp_SSE.htm
I personally have three SimpleSE's:
The low power amp uses 6V6 tubes in triode mode, an Allied 6K56VG power transformer, and Edcor XSE15-8-5K OPT's. This began as an experiment to verify the combination, but sounds so nice that I can't part with it. It makes about 1.5 watts.
The high powered amps use EL34's or KT88's or even 6L6GC's. I use an Allied 6K7VG power transformer. And an OPT with a 5K ohm primary impedance.
My industrial amp currently uses Transcendar 3K ohm OPT's made for 300B use (Ebay). I am running my 8 ohm speakers on the 4 ohm taps for a 6 K ohm load. These transformers do NOT have the UL tap so ultralinear operation is not available. This amp makes 6 to 8 watts in triode mode.
I have another SimpleSE that uses Hammond 1628SEA's. These transformers have the best bass by far since they are huge by comparison (11 pounds). The response is a bit weak in the upper highs (above 15 KHz) and they are over $100 each. In UL mode I get 10 to 14 watts.
For a good low budget alternative use the Edcor XSE15-8-5K OPT's. They have raised the price on these guys to $19 each. If your speakers don't have much bass below 70 Hz (most small speakers) these are a good alternative to high priced transformers. They worked good with my Yamaha speakers that have a 7 inch woofer, but I opted for a bigger transformer for use with my 15 inch speakers in the living room.
Other OPT's with a 4.8 to 6 K ohm primary will work. I use the Allied 6K7VG power transformer (made by Hammond) because of its low cost $47. A Hammond 274BX will work, but it is essentially the same transformer for more money. Other 750 VCT @ 175 mA transformers will work too.
Another possibility is to go the conventional route and use a lower B+ voltage with a 2.5 to 3.6 K ohm transformer. I have built amps like these for others, but I prefer the dynamics of a higher voltage and a higher load impedance. If you want to try this, you need a power transformer that puts out 600 to 650 VCT at 175 mA with 5 and 6.3 volt windings. The Transcendar 300B OPT, a One Electron UBT-3, or a Hammond 1627SEA can be used. I used some surplus 650 VCT power transformers and Transcendar OPT's.
Assembly manual:
http://www.tubelab.com/AssemblyManualSimpleSE/StartHere_SSE.html
Industrial amp:
http://www.tubelab.com/Industrial1.htm
Fisher Cabinet amp:
http://www.tubelab.com/AssemblyManualSimpleSE/FisherCabinetAmp_SSE.htm
Don't want to thread-jack, but I was planning on building a pair of bookshelf speakers using the Fostex 127e in the standard 10 litre bass reflex enclosure recommended by Fostex. Have the drivers on order. So Dave, I am extremely interested in your 4.5 litre FE127e project as these speakers will be for my girlfriend's office, and you know how women hate big speakers... To be powered by 7 watt push pull described above.
Good luck with the project Charlie. Don't know if you have seen this thread of my SimpleSE build http://www.diyaudio.com/forums/showthread.php?s=&threadid=104475
As you have seen, George from TubeLab is very helpful on these forums. If you have any questions about the build I am sure he will offer advice. Also, I am happy to help as well, but obviously my knowledge and experience is very low compared to the experts here.
I hope you enjoy the project and the end results too!
Cheers,
Chris
Good luck with the project Charlie. Don't know if you have seen this thread of my SimpleSE build http://www.diyaudio.com/forums/showthread.php?s=&threadid=104475
As you have seen, George from TubeLab is very helpful on these forums. If you have any questions about the build I am sure he will offer advice. Also, I am happy to help as well, but obviously my knowledge and experience is very low compared to the experts here.
I hope you enjoy the project and the end results too!
Cheers,
Chris
arnoldc said:Thank you so much Dave. Hope to see "small" plans on your site soon
chrish said:
The 2nd prototype went out for an audition last night... the fellow has to downsize his speakers due to GFAF. Reports are that from the body language alone, he liked them and she loved them
Version 3 is intended to get a tad more satisfying bass from them, and to get a more pleasing appearance out of them (the 1st protos didn't sound as good as the 1st but looked better)
dave
Attachments
chrish said:
We are at the have to build them to fine tune them stage... that got a set-back today as Chris broke a few toes and will need to mend before he can do more boxes.
I'm happy to privately release the plans for the ones playing in the picture. They sound fine, i just think i can get them to look a bit better and (maybe) get the impression of a bit more bass out of them without sacrificing the control these have -- the quick & dirty prototypes had more, but less controlled bass (and got killed in the mids -- too narrow a box) so i think the bass tuning would gain from being a bit closer to the Q&Ds. Both boxes have the same "alignment", the ones shown just pushed more aperiodic by the long high aspect ratio port.
Caveat: All comments are about sonics with our modified drivers.
dave
I would also be interested in building these speakers. I have been enroled in a wood shop class at a local community school for over a year. They have a nice shop complete with a very knowledgeable instructor. I would even be willing to purchase a pair of drivers and make a few sets of ugly test cabinets out of cheap material (plywood or MDF) before making nice ones.
I have fair wood working skills but zero modern speaker building knowledge other than basic guitar cabinets and my "old radio speakers".
Email me if you want to share the plans in exchange for another "beta tester".
The "old radio speakers":
http://www.tubelab.com/MySystem.htm
I have fair wood working skills but zero modern speaker building knowledge other than basic guitar cabinets and my "old radio speakers".
Email me if you want to share the plans in exchange for another "beta tester".
The "old radio speakers":
http://www.tubelab.com/MySystem.htm
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.