Tube Amp Kits

nikolas812
nikolas812 Posts: 2,915
edited April 2009 in DIY, Mods & Tweaks
I just bought a bare PC board from the Tube Lab. http://www.tubelab.com/

And I have absolutely know idea what i am doing.:) I just thought it would be fun to try and build a tube amp with the parts I want to use...

I have been reading at the Tubelab website for a few hours straight now. And I feel fairly confident I can build the amp. The Details and instructions are very good and seem fairly simple to follow.. Except for the Power side of things..

So I have pretty much sourced all of my parts except for.

Output Transformer ( I need two)
Power Transformer
Power Choke
Auxiliary power supply cap



I am wanting to run KT88's and pull as much power out of them as I can.

But I have no idea what to buy for the power side or if it even matters. I am totally lost.

I just bought the board today so it probably won't even be here for week.

But am trying to source all of my parts so I can get an idea of total money involved in the project..

So if anybody can point me in the right direction for the items listed it would be appreciated.. If I can figure out the correct ones to get I believe I would be able to bring the amp to 100% once I get all the parts. I just need to make sure I get the correct ones.:)







Nick
Post edited by nikolas812 on
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  • nikolas812
    nikolas812 Posts: 2,915
    edited February 2009
    ..............
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  • nikolas812
    nikolas812 Posts: 2,915
    edited February 2009
    If anybody has any suggestions I open to them.


    But I just found this place that probably has an answer to anything I come across...:cool:

    http://www.diyaudio.com/forums/showthread.php?s=&threadid=135110&highlight=





    Nick
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  • zingo
    zingo Posts: 11,258
    edited February 2009
    You are a man who's not afraid of a challenge and I like that! If you have specific questions that you can't find the answer to here, DIYaudio.com is a great place to go and has given me tons of help.

    I would try finding a schematic that uses KT88s that someone else has already designed and built. It will save a lot of headaches and dead ends. I would start with this website as it has the published schematics of many commercially available amplifiers: http://www.drtube.com/audioamp.htm The MC275 uses KT88s... :D
    Jake
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  • nikolas812
    nikolas812 Posts: 2,915
    edited February 2009
    Thanks. But I couldn't read a schematic to save my life...

    I took a look at the Mac schematic. It looked like some alien life form wrote it.:confused:



    I need specific part numbers.:D


    I'm pretty sure DIY forum has it covered though. There are TONS of people building these things over there. From mild to wild.....



    Nick
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  • strider
    strider Posts: 2,568
    edited February 2009
    Are you tackling the Simple SE?
    Wristwatch--->Crisco
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  • strider
    strider Posts: 2,568
    edited February 2009
    Don't know if you caught this page or not, Nick, but it's got a run down of output and power trannies, as well as choke and power supply cap numbers.
    Wristwatch--->Crisco
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  • fredv
    fredv Posts: 923
    edited February 2009
    Nick,
    You can search diyaudio or use strider's link to determine what components to use. Stuffing the board should be relatively simple. A couple areas seem to be problematic,
    1. avoid using the solid state diodes, the IXY parts that is recommended doesn't seem to be he same and often shorted and kills the tube rectifier. In short, just use the tube rectifier.
    2. The standby also seems to cause some current inrush issue that can kill the tube rectifier. So, don't use the standby switch.

    To me, the hardest part is to build the chassis. It is taking forever, given the limited amount of tools (and skills) that I have :D I am making progress nevertheless ;)

    -fredv-
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  • nikolas812
    nikolas812 Posts: 2,915
    edited February 2009
    fredv wrote: »
    Nick,
    You can search diyaudio or use strider's link to determine what components to use. Stuffing the board should be relatively simple. A couple areas seem to be problematic,
    1. avoid using the solid state diodes, the IXY parts that is recommended doesn't seem to be he same and often shorted and kills the tube rectifier. In short, just use the tube rectifier.
    2. The standby also seems to cause some current inrush issue that can kill the tube rectifier. So, don't use the standby switch.

    To me, the hardest part is to build the chassis. It is taking forever, given the limited amount of tools (and skills) that I have :D I am making progress nevertheless ;)



    Yes. I am tackling the Simple SE.;)

    I have also addressed all of the problems stated above. I found most of them with the extensive reading I did at the DIYforum. Plus I have a thread started over there and a couple of guys are walking me through the problems.

    They have also showed me a good power supply that works good with the KT88's. Its got a lot of voltage and pulls about the most you can out of the KT88's.


    The chassis is the about the most exciting part for me because of the my back ground. I have tons of material and resources and knowledge from working at a body shop for most of my life. The chassis I plan to make will be the balls for sure.:cool: I'm pretty sure the color will be a candy apple red or some sort..


    Can't wait to get things rolling. I will keep this thread updated with plenty of pics...


    Heres a link to my thread at the DIYforum...

    http://www.diyaudio.com/forums/showthread.php?s=&threadid=138527


    Cheers

    Nick
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  • schwarcw
    schwarcw Posts: 7,338
    edited February 2009
    If you are into DIY tube kits, check out Hagerman Tech Hagtech.com. He's an engineer with vast expereience. No snake oil here. His phono stage products can't be touched without dropping a whole lot of cash. The Coronet2 will cost you about $500 to build but you can't find a better phono stage for less than $3K. He also got a batter powered phono stage for about $40, fully assembled for about $150. Impressive specs and sound.
    Carl

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  • nikolas812
    nikolas812 Posts: 2,915
    edited February 2009
    schwarcw wrote: »
    If you are into DIY tube kits, check out Hagerman Tech Hagtech.com. He's an engineer with vast expereience. No snake oil here. His phono stage products can't be touched without dropping a whole lot of cash. The Coronet2 will cost you about $500 to build but you can't find a better phono stage for less than $3K. He also got a batter powered phono stage for about $40, fully assembled for about $150. Impressive specs and sound.



    I have checked out the Hagerman stuff. He didn't have anything I was interested in for a first time build.

    I might be interested in one of his phone stages a little further down the road though...





    Nick
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  • MillerLiteScott
    MillerLiteScott Posts: 2,561
    edited February 2009
    Nick

    Look at the S-5 tube amp kits. Or if you want to spend a little more money look a the Dynaco ST-35 or ST-70 kits. I am terrible at linking stuff so just google them.

    Scott
    I like speakers that are bigger than a small refrigerator but smaller than a big refrigerator:D
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  • nikolas812
    nikolas812 Posts: 2,915
    edited February 2009
    MillerLiteScott wrote: »
    Nick

    Look at the S-5 tube amp kits. Or if you want to spend a little more money look a the Dynaco ST-35 or ST-70 kits. I am terrible at linking stuff so just google them.

    Scott




    I've looked at all of them and didn't like any of them for one reason or another...

    I didn't want to build an out of production amp. And UGLY one at that.

    And the s-5 kits didn't supply enough power or options that I wanted.


    I pretty much just want a PC board and build everything around it.


    I don't know if you've read the whole thread but I have already bought the board and some tubes and parts already.

    I guess I should have named the thread Simple SE Build or something like..


    Thanks for the input though.

    But I read and searched threads for 5 hours straight before I found what I was looking for...



    So as soon as the parts start arriving I'll start taking pictures of the build and posting information about the build...




    Nick
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  • MillerLiteScott
    MillerLiteScott Posts: 2,561
    edited February 2009
    Sorry Nick.

    How much power are you expecting from the Simple SE with the KT 88's.

    I would also like to build a tube amp, just to build one. I really don't have a use for one with my current set up(s).

    Scott
    I like speakers that are bigger than a small refrigerator but smaller than a big refrigerator:D
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  • nikolas812
    nikolas812 Posts: 2,915
    edited February 2009
    Probably between 18 and 25wpc and the amp will be switchable between triode and ultra linear mode.

    With the power trannys I am putting in it, it should be into the 20's for sure...:cool: Thats about the most you can pull out of a single KT88 I think..









    Nick
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  • Hobbyguy
    Hobbyguy Posts: 317
    edited February 2009
    So are you going to make your own tube preamp as well?
    http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=300281662130&ssPageName=ADME:X:AAQ:US:1123
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  • nikolas812
    nikolas812 Posts: 2,915
    edited February 2009
    Eventually....



    But I will have a volume pot on this amp so I won't need one. It will be driven by a 5AR4 Rectifier Tube...






    Nick
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  • Hobbyguy
    Hobbyguy Posts: 317
    edited February 2009
    Very cool thread.
    Will enjoy seeing the pictures.
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  • strider
    strider Posts: 2,568
    edited February 2009
    Hobbyguy wrote: »
    So are you going to make your own tube preamp as well?
    http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=300281662130&ssPageName=ADME:X:AAQ:US:1123

    Just a word of caution regarding that Ebay seller, Audiotekxxx, there are multiple threads on diyaudio.com where they're being accused of all sorts of unsavory practices. I've had no experiences with them so it's hearsay to me, just wanted to give a heads up.


    edit: post #4 in the thread linked to above has links to other threads regarding this seller.
    Wristwatch--->Crisco
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  • nikolas812
    nikolas812 Posts: 2,915
    edited February 2009
    Thanks!

    I had no intention of buying anything from him...


    But its a good heads up for anybody else reading the thread..




    Nick
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  • fredv
    fredv Posts: 923
    edited February 2009
    nikolas812 wrote: »
    Probably between 18 and 25wpc and the amp will be switchable between triode and ultra linear mode.
    Nick
    Hi Nick,

    In triode mode, it will be more like 10 wpc. UL will probably give you close to 18. A thing to keep in mind, it is not the PT the factor limiting the power (both the Hammond 374BX or Allied PT's will do, I have both). It is the tube and the OPT. The Transcendar link I posted to you at Diyaudio is only SE, no UL as Chris pointed out, and is only 10W. I have the TT-018-OT which has 4 and 8 ohm taps, 50% screen tap for UL, and 15W rating. To me, the dual secondary tap is more important as I would like to use different speakers for fun :-)

    -fredv-
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  • nikolas812
    nikolas812 Posts: 2,915
    edited February 2009
    fredv wrote: »
    Hi Nick,

    In triode mode, it will be more like 10 wpc. UL will probably give you close to 18. A thing to keep in mind, it is not the PT the factor limiting the power (both the Hammond 374BX or Allied PT's will do, I have both). It is the tube and the OPT. The Transcendar link I posted to you at Diyaudio is only SE, no UL as Chris pointed out, and is only 10W. I have the TT-018-OT which has 4 and 8 ohm taps, 50% screen tap for UL, and 15W rating. To me, the dual secondary tap is more important as I would like to use different speakers for fun :-)



    I wasn't going to get the ones on ebay. I am inquiring about a pair from Transcender with optional UL taps..

    The Model is - Transcendar SE 5k 8ohm 10w. These are the ones I am inquiring about.

    These are the ones Ty used and I thought he said somewhere in his thread he was getting around 21.4 watts?? Maybe he was guessing?? He said it was about the max for the tube...


    Nick
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  • fredv
    fredv Posts: 923
    edited February 2009
    The ebay link is indeed SE 5K 8ohm 10W except no UL. I thought that was what Ty had, no?

    Unless Gery (owner of Transcendar) is really really conservative, it is hard to believe you can get 21.4W from a 10W OPT. The OPT will be well saturated before approaching that output. I can be wrong and certainly hope so. If so, my 15 watter from Gery can be good for 25W :-) If I interpret correctly, the 21.4 watts might be the max that can be squeezed from the tube which probably not the case for most of the time. Quite frankly, I seldom crank more than 2 watts per channel even with some not too efficient speakers. Just for comparison, attached is a picture of 3 SE OT's that I have:
    - The biggest, Hammond 30W
    - Mid-size, Transcendar 15W
    - The smallest, James, 10W
    All have dual 8/4 ohm taps and UL. The irons are the most important and expensive of all the parts. Take your time to research what you want, don't rush.

    -fredv-
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  • nikolas812
    nikolas812 Posts: 2,915
    edited February 2009
    Thanks

    I wasn't debating it. I have no idea. I just thought I remember reading about it somewhere..


    Either way I think it will be just fine for my application. I do want UL taps though so the ebay OPT's won't work.

    Those are also the exact same ones Ty has. Spec wise anyways minus UL taps. His are from Transcendar with UL taps. Which is probably where mine will be coming from..

    Unless you have some for sale.:D



    Nick
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  • fredv
    fredv Posts: 923
    edited February 2009
    Sorry, if I sound like debating, I apologize. Just want to share what I know, and I am not always right either :-)

    Gery is very responsive, I am sure you will get a reply from him shortly. In fact, I didn't buy my Transcendar's from him. I emailed him for the specs, and he replied me in half day.

    I wish you were nearby that I could ask you to help painting the rough aluminum plate. For now, I probably will have to settle on spray paint. Any tips on what to use to patch the deep scratch of the plate before painting?

    -fredv-
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  • nikolas812
    nikolas812 Posts: 2,915
    edited February 2009
    I have a thread started here offering my services to fellow polkies. You can send it to me if you like. And I I can fill the scratches primer and paint it..

    Any tips on what to use to patch the deep scratch of the plate before painting?


    Not really. If there not too terribly deep you can try and find a can of high build primer. And primer the heck out of it.. Then sand it smooth with a grit sand paper and spray paint it..


    You might have to go to a auto paint supply store to get the high build primer in a can. But it might do the trick and would be a lot cheaper than me doing it...

    Gery is very responsive, I am sure you will get a reply from him shortly. In fact, I didn't buy my Transcendar's from him. I emailed him for the specs, and he replied me in half day.


    I emailed him a day or two ago and still have not heard back from him.. I thought maybe because it was the weekend?:confused:

    I sent the email to the email address found on this page.. http://transcendar.com/



    Nick
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  • nikolas812
    nikolas812 Posts: 2,915
    edited February 2009
    I've got about 90% of my parts now. Enough to start on my board and chassis.

    I drilled some holes and mounted my bottom plate to my chassis and added some rubber feet..


    A little bit after I did that my parts from Digi Key arrived and my tubes from the tubestore arrived.


    Which was awesome because the Tubestore made and error and sent me the wrong tubes. They sent me Winged C's instead of the Sovteks I ordered. The winged C's are what I wanted in the first place but I didn't want to spend the money. The winged C's cost almost twice as much as the Sovteks. Needless to say I was VERY happy!


    I stuggled at first with soldering. But after a few resistors were installed I started to fall into a groove. I still stuggled here and there. But for the most part I think they turned out OK.

    If anybody sees anything wrong please point it out to me...

    I took 21 pics of the progress today. But I'll limit this post to 8.


    I also didn't install the FREDS or the Heatsink Diodes. I didn't install the Heatsink and diodes because there wasn't a screw and nut with my parts. So I'll have to go to the hardware store tomorrow before I can install them..


    It took me about 3.5 hours to complete the board....


    Cheers



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  • ShinAce
    ShinAce Posts: 1,194
    edited February 2009
    Looking good.

    Have a good look at R13. Doesn't look like there's much solder bonded to the lead.
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  • nikolas812
    nikolas812 Posts: 2,915
    edited February 2009
    Thanks.


    I just took a look at R13. The pic is deceiving. Thats about one of the best looking solder joints on the whole board...


    Thanks for taking a look...




    Nick
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  • zingo
    zingo Posts: 11,258
    edited February 2009
    That looks great! I love how those KT88s dominate that board.



    Skoal special eh? :p
    Jake
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  • nikolas812
    nikolas812 Posts: 2,915
    edited February 2009
    zingo wrote: »
    I love how those KT88s dominate that board.





    Me too. I had never even seen a KT88 until today.


    Hence the reason for building a KT88 version.... I can't wait to hear them.



    Nick
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