I have plenty matched sets of 2SK2013/2SJ313 for sale. The FETs were curve traced and matched for both Vgs and Yfs. Obviously 100% genuine Toshiba devices from trusted sources.
Cost is 32 euro for NNNN-PPPP sets and 48 euro for NNNNPPPP sets (+8 euro postage, registered mail).
When I find the time, I will post a list of the available sets.
Cheers,
Nic
Cost is 32 euro for NNNN-PPPP sets and 48 euro for NNNNPPPP sets (+8 euro postage, registered mail).
When I find the time, I will post a list of the available sets.
Cheers,
Nic
I also have a set of PCBs for this build if anybody is interested (30 euro postage included). They were made by late permaneder and are of excellent quality. I'm not sure what the smaller boards are. Maybe cap multipliers. All info should be somewhere in this thread.
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Starting build
I am going to make this amp with 4 pairs, maybe run them 300mA ea. Thinking about an all 3d P2P sculpture type amp, no PCB, no veroboard. Will run from +/-25v rails that I used for my M2 project.
Starting with drill & tap 8 holes on a heatsink. The nice thing about J313/K2013's is they don't have any exposed metal so no insulators to worry about.
Using heatsinkUSA 7.38in wide extrusion, 5in tall. Same heatsink that I used for M2 so I know it can handle 1.3amps at 25v rails.
I am going to make this amp with 4 pairs, maybe run them 300mA ea. Thinking about an all 3d P2P sculpture type amp, no PCB, no veroboard. Will run from +/-25v rails that I used for my M2 project.
Starting with drill & tap 8 holes on a heatsink. The nice thing about J313/K2013's is they don't have any exposed metal so no insulators to worry about.
Using heatsinkUSA 7.38in wide extrusion, 5in tall. Same heatsink that I used for M2 so I know it can handle 1.3amps at 25v rails.
Attachments
Really? My estimates show this size heatsink to be woefully inadequate for a constant 65W draw. Are you using a fan?
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If you haven't already ordered your components, suggest you try the Rhopoint resistors for the 2.2kR 'gain' resistors, for the 10R at the jfet (R3 & 4), and the Fet gate stoppers - the KOA's aren't bad either and far easier to find
I tried a few different 0.67R types for the source resistors but only ELFA seems to stock the Isab's but could get any .67 or 2 x 0.33s (SMD version) - ended up making my own using the 9R/metre insulated Manganin wire - for the 75R feedback resistors, used a Isabellenhutte PBH 100R in // with a 300R KOA - excellent
This amp went out on a loan and hasn't returned - drives a pair of Harbeth HL5+
I tried a few different 0.67R types for the source resistors but only ELFA seems to stock the Isab's but could get any .67 or 2 x 0.33s (SMD version) - ended up making my own using the 9R/metre insulated Manganin wire - for the 75R feedback resistors, used a Isabellenhutte PBH 100R in // with a 300R KOA - excellent
This amp went out on a loan and hasn't returned - drives a pair of Harbeth HL5+
What's wrong with using 1% metal thin film resistors? I have them in 1/4w, 1/2w, 1w, and 2w. I think I have all values I need. These are nothing special but I believe are non inductive. Maybe I don't know what I don't know but I have never been able to get myself to spend 10x more on the brown sausage shaped Dales either.
If you look at the photo above you will see all robin egg blue colored metal thin film resistors - all 1% from China. Qnty 20 x 2w ones cost about $1 a bag.
If you look at the photo above you will see all robin egg blue colored metal thin film resistors - all 1% from China. Qnty 20 x 2w ones cost about $1 a bag.
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What's wrong with using 1% metal thin film resistors?
Nothing wrong at all altho some of the cheap china ones sometimes deliver a less than satisfactory sound, IMO
The benefits of the 'better' quality resistors are in the total component package - for example, the components supplied with the 'Jim's Audio' F5 amp has a particularly 'thin and hard' sound even when you use the extra pot on the jfets to change some of the H3 to H2 - some people/ sound systems benefit from this to add a certain 'cut' to the sound but the amp is pretty 'bright' anyway - this is a personal 'thing' I hasten to add.
The 'juma' version has a much 'softer' nature to the sound without sacrificing any of the transients, detail, dynamics, etc due to the reduced feedback, local degeneration, etc and the Manganin type resistors emphasize this characteristic (85% copper content) but they're instrumentation resistors and hence more expensive
The next best 'soft sounding' ones without the high price tag would probably be the Speer KOA type of film resistors and readily available - on the other end of the spectrum, you may find the Susumi resistors the most detailed without the high price of the TC2575s, etc
I've found that the high cost and effort of sorting out the transistors is best matched with spending a bit more on the other components be it resistors, caps and especially the power supplies - this is just my own personal opinion, mind you
Nothing wrong at all altho some of the cheap china ones sometimes deliver a less than satisfactory sound, IMO
The benefits of the 'better' quality resistors are in the total component package - for example, the components supplied with the 'Jim's Audio' F5 amp has a particularly 'thin and hard' sound even when you use the extra pot on the jfets to change some of the H3 to H2 - some people/ sound systems benefit from this to add a certain 'cut' to the sound but the amp is pretty 'bright' anyway - this is a personal 'thing' I hasten to add.
The 'juma' version has a much 'softer' nature to the sound without sacrificing any of the transients, detail, dynamics, etc due to the reduced feedback, local degeneration, etc and the Manganin type resistors emphasize this characteristic (85% copper content) but they're instrumentation resistors and hence more expensive
The next best 'soft sounding' ones without the high price tag would probably be the Speer KOA type of film resistors and readily available - on the other end of the spectrum, you may find the Susumi resistors the most detailed without the high price of the TC2575s, etc
I've found that the high cost and effort of sorting out the transistors is best matched with spending a bit more on the other components be it resistors, caps and especially the power supplies - this is just my own personal opinion, mind you
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