Tenson 0 Report post Posted August 17, 2003 I want a headphone amp for the K1000's but I don't have much money left really! So what I want to do id a DIY tube amp for them. At the moment I am thinking of building an RKV. I have seen 'porn' of it and it looks pretty simple. Also I have sent an email to AudioValve asking for a circuit diagram. I want to make it as a single-ended amp and also I think I can cut out the part that does impedance matching as I will only be using it on the K1000's and they are 120Ohms. Hopefully they will be helpful, I told them I was a student and there is no way I can afford one normally so they aren't going to loose anything by letting me have a copy! So I wanted your advice, do you think the K1000's will be okay on an OTL? The voltage would have to be pretty high obviously so that's the main concern. Second is has anybody tyred this before?! Or something like it. If so then I would greatly appreciate any circuit diagrams and tips etc.. Thakyou! Share this post Link to post Share on other sites
N@Z 0 Report post Posted August 17, 2003 Alternatively, you could try the ASL Wave Monoblocks if you already have a preamp. Share this post Link to post Share on other sites
Tenson 0 Report post Posted August 17, 2003 Yes, I have just been looking at ASL a few min ago! The AQ1005 DT looks very nice and is the recommended by headroom. Also they nicely give the circuit diagrams on their site! But I think the RKV looks like it would be easier to build and less costly as there are no output transformers to buy. That is another reason why I like the look of the AQ1005 DT more than the monoblocks. In a monoblock you have twice the number of power transformers to buy Share this post Link to post Share on other sites
N@Z 0 Report post Posted August 18, 2003 I thought the Wave mono blocks only cost less than US$300/pair. Share this post Link to post Share on other sites
Tenson 0 Report post Posted August 18, 2003 Do they?! The page I was looking at had a broken link for them. But if they are that cheep can they really be that great? I'll look into them, cheers. Share this post Link to post Share on other sites
N@Z 0 Report post Posted August 18, 2003 Yes their site seems to be down. I tried a google search for you: http://search.netscape.com/nscp_results.ad...blocks&x=10&y=6 Some of the links are old so the prices may not be as low as US$99 each. Share this post Link to post Share on other sites
antness 0 Report post Posted August 18, 2003 Pete Millett designed an amp for the AKG K1000. You can find building information here: http://www.pmillett.addr.com/ecc99_srpp_he...adphone_amp.htm Share this post Link to post Share on other sites
Rameish 0 Report post Posted August 18, 2003 Tenson, I doubt it very much Audio Valve will send you a schematic. There are some valve designs on headwize.com Good Luck. Share this post Link to post Share on other sites
Firefox 0 Report post Posted August 18, 2003 Go to Headwize and build a Szekere's amplifier with a gain stage. Use a decent opamp on the gain stage; ie. AD8620, OPA2228 etc. Get decent resistors like Vishay Dales or High temp. metal films and be sure to use the LM317(T) constant current source. Build also a good regulated power supply for the amp. You should be able to pump enough current into the K1000's depending on the transistor used. Share this post Link to post Share on other sites
Tenson 0 Report post Posted August 19, 2003 Thanx for all the suggestions guys! Although the wave monoblocks are, I'm sure, very good for the money! From reading the reviews they say that they lack midrange detail and finesse, which is not what I'm looking for. They are also push/pull which is not quite what I am looking for. But I have to say I am still tempted by them Such sexy little amps Maybe if I can't decide on a design then I will end up with them... I found Pete's design as well, it looks pretty complex! Nice cheep valves though. Audio Valve has not even replied! lol.. but they may do tomorrow, I know they will probably say bog off. But if they don't.. An opamp based design will most likely sound too harsh Firefox, I want something to tame the brightness of the cans a bit. I said before that the ASL AQ1005 DT was what I was thinking of doing if Audio Valve don't gimme a circuit schematic. But I found out that it is VERY expensive to get hold of the 300B valves it uses in England. So now I am looking at this http://www.tubehifi.com/MG_SPM15.HTM very simple design with easy to obtain tubes. I have emailed Sowter asking how much some transformers will set me back. I am on a tight budget so we will see how it turns out Share this post Link to post Share on other sites
N@Z 0 Report post Posted August 19, 2003 When I asked Music By Design SG they quoted $1200 per matched pair (including wooden presentation box) for the Western Electric 300B! Share this post Link to post Share on other sites
Mackie 0 Report post Posted August 19, 2003 When I asked Music By Design SG they quoted $1200 per matched pair (including wooden presentation box) for the Western Electric 300B! Gees.......they must have picked up the smell of wealth around U. Just kidding. Share this post Link to post Share on other sites
N@Z 0 Report post Posted August 19, 2003 how much are they supposed to be actually? The reason I asked was I auditioned the $7K Cary 300SEI integrated with headphone out. How about building a clone Cary Tenson! Share this post Link to post Share on other sites
Mackie 0 Report post Posted August 19, 2003 I don't know Naz....1200 for a pair of tubes.....I reckon my facial expression would have been very awkward if I were to be in the same situation........ain't no poker face U know. Sorry for the OT. Share this post Link to post Share on other sites
Firefox 0 Report post Posted August 19, 2003 An opamp based design will most likely sound too harsh Firefox, I want something to tame the brightness of the cans a bit. Actually, a well built Szekere's amplifier with good resistors like Holco's & caps like Cerafines can and will sound like tubes on steroids. Share this post Link to post Share on other sites
