Hi, guys!
Considering lowering R13 to 300R or 270R iot lowering gain a little. I asked 6L6 about it, and he says this will reduce output power a bit.
I considered asking him this in a PM, but since I can’t find the answer in either my head or looking through the forum (I know, it is probably here somewhere), I ask here so that others might learn.
What is the performance consequence of reducing R13?
Regards,
Andy
Considering lowering R13 to 300R or 270R iot lowering gain a little. I asked 6L6 about it, and he says this will reduce output power a bit.
I considered asking him this in a PM, but since I can’t find the answer in either my head or looking through the forum (I know, it is probably here somewhere), I ask here so that others might learn.
What is the performance consequence of reducing R13?
Regards,
Andy
Hi guys!
These good for the FE?
9-11mA IDSS. Nelson says i. The manual his devices were around 10ma.
Source also has 7-9mA, which might be more suitable for allround FW projects?
Toshiba 2SJ74 + 2SK170 LAB MATCH QUAD to 0.03mA & 4mV (9-11mA range "BL" "B") | eBay
I currently have Linear devices, but it seems IDSS is a bit lowish compared to the specced ones in article.
What about reliable sources for 2SJ113/2SK2013? Anyone? A bunch selling at eBay, but difficult to verify reliable sources. There are some US companies on there though, but could be shells for all I know.
I do have a running BA-3. call this process a possible pimp my ride kinda thing.
Cheers,
Andy
These good for the FE?
9-11mA IDSS. Nelson says i. The manual his devices were around 10ma.
Source also has 7-9mA, which might be more suitable for allround FW projects?
Toshiba 2SJ74 + 2SK170 LAB MATCH QUAD to 0.03mA & 4mV (9-11mA range "BL" "B") | eBay
I currently have Linear devices, but it seems IDSS is a bit lowish compared to the specced ones in article.
What about reliable sources for 2SJ113/2SK2013? Anyone? A bunch selling at eBay, but difficult to verify reliable sources. There are some US companies on there though, but could be shells for all I know.
I do have a running BA-3. call this process a possible pimp my ride kinda thing.
Cheers,
Andy
Which naturally begs the question:
1: Are Toshiba JFETs audibly better than those from Linear?
2: Is there an audible difference between 6 and 8mA JFET bias on a BA-3 FE?
3: How significant is the audible difference between Fairchild FE output MOSFETs and 2SJ313/2SK2013 in the BA-3 circuit?
4: Is the high price and risk of getting fake 313/2013s worth it?
I allready have the LS’es and plenty Fairchilds.
Regards,
Andreas
1: Are Toshiba JFETs audibly better than those from Linear?
2: Is there an audible difference between 6 and 8mA JFET bias on a BA-3 FE?
3: How significant is the audible difference between Fairchild FE output MOSFETs and 2SJ313/2SK2013 in the BA-3 circuit?
4: Is the high price and risk of getting fake 313/2013s worth it?
I allready have the LS’es and plenty Fairchilds.
Regards,
Andreas
1.here, no
2.not very likely
3.some; not on quality level, more on preference and taste level; take in account that some ppl can't even hear that difference
4.how can I tell that for ya?
take a look at schematic of FE - Iq marked as 8mA, with 10R source resistors in place; you think these are 8mA Idss or ?
what's wrong with using da brain , these days ?
2.not very likely
3.some; not on quality level, more on preference and taste level; take in account that some ppl can't even hear that difference
4.how can I tell that for ya?
take a look at schematic of FE - Iq marked as 8mA, with 10R source resistors in place; you think these are 8mA Idss or ?
what's wrong with using da brain , these days ?
I could add:
3: SE I could hear a little difference. Balanced I could hear and measure a significant difference.
4: Prakit might still have some: FS: TOS 2SK2013/2SJ313
Cheerio
3: SE I could hear a little difference. Balanced I could hear and measure a significant difference.
4: Prakit might still have some: FS: TOS 2SK2013/2SJ313
Cheerio
1.here, no
2.not very likely
3.some; not on quality level, more on preference and taste level; take in account that some ppl can't even hear that difference
4.how can I tell that for ya?
take a look at schematic of FE - Iq marked as 8mA, with 10R source resistors in place; you think these are 8mA Idss or ?
what's wrong with using da brain , these days ?
My brain is not as big as yours, you know this allready!
Plus I allready have extra source resistors ordered to try. But don’t wanna mess with original circuit if it is futile and pointless.
Andy,
If you want to try the 2sk2013/2sj313 then I also second the suggestion to contact Prakit.
If your goal is to get 8mA with 10R degeneration then you should order the parts from Punkydawgs and ask for about 10mA. (I don't think you can request a specific Idss for the store LSK/LSJ parts).
Dennis
If you want to try the 2sk2013/2sj313 then I also second the suggestion to contact Prakit.
If your goal is to get 8mA with 10R degeneration then you should order the parts from Punkydawgs and ask for about 10mA. (I don't think you can request a specific Idss for the store LSK/LSJ parts).
Dennis
Thanks, guys!
I allready msged Prakit yesterday, hoping for a reply. But if that fails I just wanna know it is worth the extra effort.
Msged a builder here in Norway today, but looks like he is trying to push alternative parts on me. No dice.
I’ll msg punkydawgs and see what happens 🙂
On another note, got my 2SK209s today. Need to reread 6L6 and others methods for getting them to correct orientation. No problem soldering, but keep slipping and looking crooked. So gonna try over again.
I read about a tape trick, gonna check that out more closely. Parts from 6L6, need to take good care of them.
Andy
I allready msged Prakit yesterday, hoping for a reply. But if that fails I just wanna know it is worth the extra effort.
Msged a builder here in Norway today, but looks like he is trying to push alternative parts on me. No dice.
I’ll msg punkydawgs and see what happens 🙂
On another note, got my 2SK209s today. Need to reread 6L6 and others methods for getting them to correct orientation. No problem soldering, but keep slipping and looking crooked. So gonna try over again.
I read about a tape trick, gonna check that out more closely. Parts from 6L6, need to take good care of them.
Andy
Toshiba Mosfets+Jfets were totally worth it for me. I cannot say if it were the Jfets or the Mosfets that made the difference. According to ZM its the Mosfets.
Here you can get the Jfets:
Toshiba 2SJ74 + 2SK170 Lab matched OCTET zu 0.03mA/4mV (10mA Reichweite) | eBay
Cheerio
Here you can get the Jfets:
Toshiba 2SJ74 + 2SK170 Lab matched OCTET zu 0.03mA/4mV (10mA Reichweite) | eBay
Cheerio
Thought it might be like that, that is why I am so interested in the «upgrade». Can you describe the audible changes a bit more in detail?
Thanks!
Andy
Thanks!
Andy
In SE i heard a bit more clarity and detail. I guess it gets overwhelmed with the drekload of H2 from the complementary output stage in my case, so the difference is small single ended.
In bal. I heard much more detail and clarity and less harshness. Unfortunately I measured before listening so might have been biased. 😀
The price for the Mosfets is much less than what I splurged e.g. on the caps and the benefit much greater. 😉
In bal. I heard much more detail and clarity and less harshness. Unfortunately I measured before listening so might have been biased. 😀
The price for the Mosfets is much less than what I splurged e.g. on the caps and the benefit much greater. 😉
Attachments
And there a set of quad matched J74 and K170s at 10.14ma are on their way from Punky. What a day, I wiuld have never thought it. Smooth sailing! Looking forward to this.
Looking forward to see the return adress on the letter/package. Are we talking wizards assistant or is that too far fetched? Lab matched, storage from the good old days. This is not just anywhom...
