[UntilThen]

I would be very interested in what you think of the silver cable if you can let me know when you try it. As I said I was thinking of getting pure silver headphone cable but not speaker cable so that made me sit up with interest.

I gather your Elekit is a diy amp, maybe there was an assembly fault? It's strange the tube was working fine one day an not on the other.

No fault in the diy amp because it was made by a French guy living in Australia and he's an experienced diy person. Not sure why he sold off the Elekit after one year and there were many who were trying to fight for that amp before me but I was the strongest in the school yard and I got the amp... and the rest were on the ground groaning in agony.

I had the Elekit TU-8200 since the 1st of Jan 2021. That's 2 months and 18 days of pure bliss and I was rolling and rolling and rolling... it was perfect. Then 807 came. Might as well be 007. Anyway let's forget about Elle kid.

Now onto the silver cable. He i.e cable man also made me a silver xlr balanced cable for my LCD-3f. So silver headphone cable connect to the speaker cable and then taps ! I'll tell you what happens tomorrow. I want to do that to a few muscular amps. Amps as big as wrestlers. I'll let you know what happens.

Well the probable outcome might be I find it too bright and might just throw the silver away and beg for some copper.

Now if you'll excuse me I'm in the middle of watching Equalizer 2... you know Denzel Washington? I'll be back.

 

[hypnos1]

Auto-bias is another word for cathode bias. You have a resistor from cathode to ground, with a bypass cap. You size the resistor to get a certain voltage drop across it. While the grid is at zero V, the voltage drop across the cathode resistor becomes the negative bias voltage for the tube as you measure tube voltage in relation to cathode, always.

It's called "auto-bias" because even though Odyssey will be optimally biased for KT88 output tubes other tubes will still find an operating point and work in the amp as the cathode resistor will always drop some voltage. But, you can only bias the amp "optimally" for a certain tube even with cathode bias. Some tubes bias almost the same while others completely different. The one thing that would cause a output tube not work in Odyssey is if it can't handle the high anode voltage. The tube will then red plate and let out the magic smoke!

You then have fixed bias, also known as grid bias. Infinity and Eternity uses grid bias. The input stage in Oblivion also. With fixed bias you apply a negative voltage to the tube grid and ground the cathode to get your negative voltage. Remember, you measure voltage in relation to cathode. So, grid -> cathode. You then have no option to tube roll what so ever! Unless, you have a way to adjust the negative voltage applied to the grid. This is what I've done with the tube rolling add-on in Infinity and Eternity

Thanks for sparing your precious time ST...you must be burning lots of midnight oil lol! Long may your energy resources continue...you must be a real young'un (either that or you simply plug yourself into one of your projects as you toil!! ).

And yes indeed...auto vs fixed bias - each with its own merits of course...

 

[hypnos1]

No fault in the diy amp because it was made by a French guy living in Australia and he's an experienced diy person. Not sure why he sold off the Elekit after one year and there were many who were trying to fight for that amp before me but I was the strongest in the school yard and I got the amp... and the rest were on the ground groaning in agony.

I had the Elekit TU-8200 since the 1st of Jan 2021. That's 2 months and 18 days of pure bliss and I was rolling and rolling and rolling... it was perfect. Then 807 came. Might as well be 007. Anyway let's forget about Elle kid.

Now onto the silver cable. He i.e cable man also made me a silver xlr balanced cable for my LCD-3f. So silver headphone cable connect to the speaker cable and then taps ! I'll tell you what happens tomorrow. I want to do that to a few muscular amps. Amps as big as wrestlers. I'll let you know what happens.

Well the probable outcome might be I find it too bright and might just throw the silver away and beg for some copper.

Now if you'll excuse me I'm in the middle of watching Equalizer 2... you know Denzel Washington? I'll be back.

OUCH! UT. Interesting though, as when I was researching alternatives to the 6L6 there seemed mixed views as to the 807's versatility? But perhaps it was indeed simply a bad tube which, as you said, can also happen to NOS tubes alas. Normally that kind of catastrophic failure seems to be down to either arcing across electrodes or too high a voltage on the anode?...

And as for silver, if anything in the system is over-sensitive to treble frequencies, then (good!) copper might be a safer bet. However, mono-crystal OCC silver, as with Neotech's UP-OCC offerings shouldn't cause any such problems (the opposite in fact), and also still deliver good, solid, detailed bass. As always though, the only real way to be sure is suck it and see! ...GOOD LUCK... CJ

 

[UntilThen]

Hey Colin, it seem unreal. We were chatting on Elise thread then Euforia. Now we caught up again here. Except I'm a few years older hahaha. The passion for amps has not died though but I've been through a lot of amps since Elise. Weary? A little... I feel like the journey's coming to an end but the music still sounding as fresh as yesterday. In fact it just sound better with each passing day.

This silver headphone cable for my LCD-3f is very clear indeed. It ain't too bright. Kind of open up the planar. I like it... a lot. I have a Meze copper 2.5m cable for the LCD-3f and also a Forza Audioworks Claire Hybrid HPC. Suddenly 3 cables for the LCD-3f. I have only one Forza Noir Hybrid HPC for my He1000se. It's silver/copper hybrid. I feel very content with these headphones and the various tube amps I have.

For Odyssey, I've been thinking of 2 very powerful tubes. The KT150 and EL156. Tomas says I can use them in Odyssey. It will just run cooler. Don't ask me to run 12v GU50 tubes in Odyssey. Not having that feature. Keeping it simple.

This is what I found out about the EL156 tube -
Almost fifty years ago, Telefunken introduced the EL156 as a replacement for KT88 It was used in LP mastering labs to drive cutting lathes. At the time, the tube had a ten-pin base socket,Y10-A , and wasn’t used outside recording studios. As the LP faded, so did the EL156. Some words about the original Telefunken EL156 longevity: I have found data that one of these survived like 60.000h in a laboratory PSU, at an university. I did not believe it at the time.

So maybe if I buy a pair of these, it will last me 60,000 hours...

And the KT150 tube -
With a massive plate dissipation of 70 watts, the Tung-Sol KT150 is the most powerful octal beam tetrode ever produced. A pair of KT150s can allow an amplifier with a power output approaching 300 watts to be built.
The Tung-Sol KT150 glass envelope is a special egg shaped balloon that was developed to improve thermal dissipation and maintain a superior vacuum for the best sound. The fact that the glass envelope has no flat sides means the Tung-Sol KT150 has no problems with microphonics.

 

[hypnos1]

Hey Colin, it seem unreal. We were chatting on Elise thread then Euforia. Now we caught up again here. Except I'm a few years older hahaha. The passion for amps has not died though but I've been through a lot of amps since Elise. Weary? A little... I feel like the journey's coming to an end but the music still sounding as fresh as yesterday. In fact it just sound better with each passing day.

This silver headphone cable for my LCD-3f is very clear indeed. It ain't too bright. Kind of open up the planar. I like it... a lot. I have a Meze copper 2.5m cable for the LCD-3f and also a Forza Audioworks Claire Hybrid HPC. Suddenly 3 cables for the LCD-3f. I have only one Forza Noir Hybrid HPC for my He1000se. It's silver/copper hybrid. I feel very content with these headphones and the various tube amps I have.

For Odyssey, I've been thinking of 2 very powerful tubes. The KT150 and EL156. Tomas says I can use them in Odyssey. It will just run cooler. Don't ask me to run 12v GU50 tubes in Odyssey. Not having that feature. Keeping it simple.

This is what I found out about the EL156 tube -
Almost fifty years ago, Telefunken introduced the EL156 as a replacement for KT88 It was used in LP mastering labs to drive cutting lathes. At the time, the tube had a ten-pin base socket,Y10-A , and wasn’t used outside recording studios. As the LP faded, so did the EL156. Some words about the original Telefunken EL156 longevity: I have found data that one of these survived like 60.000h in a laboratory PSU, at an university. I did not believe it at the time.

So maybe if I buy a pair of these, it will last me 60,000 hours...

And the KT150 tube -
With a massive plate dissipation of 70 watts, the Tung-Sol KT150 is the most powerful octal beam tetrode ever produced. A pair of KT150s can allow an amplifier with a power output approaching 300 watts to be built.
The Tung-Sol KT150 glass envelope is a special egg shaped balloon that was developed to improve thermal dissipation and maintain a superior vacuum for the best sound. The fact that the glass envelope has no flat sides means the Tung-Sol KT150 has no problems with microphonics.

Yo UT...it's just like old days lol . But now my time for in-depth thread involvement is much reduced alas. Occasional revisiting sure is great though....

And that KT150 is one almighty Schwarzenegger of a tube!...and looks real cool lol (running cooler would also be a bonus!). But can it match KT88's performance?...plenty research needed methinks! That EL156 also looks interesting...(your tube collection could just possibly be growing exponentially once more, mon ami!!). Ah well, enough tube talk for now I'll wager...now you can just dream of the delights to come in a few months' time. Lucky you!

ps. Glad you find that silver not too bright...and the hallmark of good silver, especially OCC, is indeed its clarity (amongst other virtues)...

 

[UntilThen]

And that KT150 is one almighty Schwarzenegger of a tube!...and looks real cool lol (running cooler would also be a bonus!). But can it match KT88's performance?...plenty research needed methinks! That EL156 also looks interesting...(your tube collection could just possibly be growing exponentially once more, mon ami!!). Ah well, enough tube talk for now I'll wager...now you can just dream of the delights to come in a few months' time. Lucky you!

I've sampled a McChanson KT150 amp only recently. Made a short opinion, laying out of my thoughts here. https://www.head-fi.org/threads/eric-mcchanson-headphone-amp.718350/post-16192442

How does it compare to the KT88? I need more time to evaluate that. Elekit TU-8200 failed at the wrong time. It was supposed to be my test bed amp until I get Odyssey. An amp to burn in my NOS tubes. I'll have to get it repaired or get an interim McChanson amp. Nah .... enough of amps.

Mon ami lol. When you say that I'm reminded of @Lorspeaker He always find it amusing when you day that.

As I said earlier, a friend is bringing over a McChanson KT77 and 300b amps. He6se Mk2 will also be here. Also a Luxman P750u. Susvara and Utopia too. Auteur and Grado GH4. It's turning out to be a mini meet in my home ! Just when I said I will wind back at my involvement in this hobby.

 

[UntilThen]

Who me, obsessed? I can stop any time I want to. But is it normal that going into this store with my wife today invoked instantaneous cravings for these bulbs' bigger musical brethren? Really, though, I could stop any time I want to.

Omg Lory you're beyond hope.

 

[UntilThen]

Auto-bias is another word for cathode bias. You have a resistor from cathode to ground, with a bypass cap. You size the resistor to get a certain voltage drop across it. While the grid is at zero V, the voltage drop across the cathode resistor becomes the negative bias voltage for the tube as you measure tube voltage in relation to cathode, always.

It's called "auto-bias" because even though Odyssey will be optimally biased for KT88 output tubes other tubes will still find an operating point and work in the amp as the cathode resistor will always drop some voltage. But, you can only bias the amp "optimally" for a certain tube even with cathode bias. Some tubes bias almost the same while others completely different. The one thing that would cause a output tube not work in Odyssey is if it can't handle the high anode voltage. The tube will then red plate and let out the magic smoke!

You then have fixed bias, also known as grid bias. Infinity and Eternity uses grid bias. The input stage in Oblivion also. With fixed bias you apply a negative voltage to the tube grid and ground the cathode to get your negative voltage. Remember, you measure voltage in relation to cathode. So, grid -> cathode. You then have no option to tube roll what so ever! Unless, you have a way to adjust the negative voltage applied to the grid. This is what I've done with the tube rolling add-on in Infinity and Eternity

I won't pretend that I understand this but I like it anyway.

 

[SonicTrance]

Thanks for sparing your precious time ST...you must be burning lots of midnight oil lol! Long may your energy resources continue...you must be a real young'un (either that or you simply plug yourself into one of your projects as you toil!! ).

And yes indeed...auto vs fixed bias - each with its own merits of course...

No problem! Well, I'm turning 39 soon so I guess I'm not THAT old, lol

As I said earlier, a friend is bringing over a McChanson KT77 and 300b amps. He6se Mk2 will also be here. Also a Luxman P750u. Susvara and Utopia too. Auteur and Grado GH4. It's turning out to be a mini meet in my home ! Just when I said I will wind back at my involvement in this hobby.

Wow! Cool stuff! Have fun!

 

[UntilThen]

No problem! Well, I'm turning 39 soon so I guess I'm not THAT old, lol

Really? So young ! Well lots of people were famous when they were young. James Dean, Beatles, Rolling Stones, ABBA?

Haha when I think of Sweden I think of ABBA, Volvo but it's a lovely country. I must visit one day !

Wow! Cool stuff! Have fun!

Yes 3 other lads are coming with their gear...... and it's raining like crazy for the last 2 days !!! and continuing into next week too. In the news, a house was washed down the river.

 

[UntilThen]

@baronbeehive you wouldn't be interested in classical, would you? I have decided to buy these 90 classical LPs... so I can listen on the weekends with a glass of wine or vodka or guiness stout ! Anything to digest classical.

https://www.stereo.net.au/forums/topic/342028-fs-90-classical-lps/?tab=comments#comment-4726522

 

[vkung]

As I took the pains to explain, the 807 tubes work well with no problems on the 1st night of ~ 4 hours. The next night, when I power it on and left it for 15 mins, fire shot up in the left tube. My guess is a faulty tube but it is NOS NIB.... which is no guarantee that it will not be faulty.

807 is a recommended tube in the Elekit TU-8200. At least by previous tube rollers of that amp - see the Elekit TU-8200 thread 1st page. I have a suspicion that it's not compatible as it is electrically equivalent to the 6L6 - which is different from the 6L6GC that is the stock tube for the TU-8200.

For Odyssey I'll have to check with Tomas which tubes are usable. He did tell me that for EL39 and EL12 spez to use 5U4G rectifier, which has a bigger voltage drop.

The only reason is that your 807 is no good. You bought a bad 807

 

[vkung]

So what was exactly the cause? Auto-bias did not worked and when you put 807 after you previously used 6L6GC something did not adjust and your amp took fire?

you have a bad 807.

 

[mordy]

you have a bad 807.

The Feliks Euforia has a built in circuit that shuts off the amp when it short circuits, and this saved my amp when there was a catastrophic tube failure.
It seems that most custom amps lack such a feature. Maybe all of them habe a fuse as protection, but I am not aware of such protective circuits in other amps and the fuse does not always protect.

 

[vkung]

FET is only $0.5. It will save your amp. Of course you can use 807 with adaptor. No matter what, TU-8200 is designed to run on 6L6GC. Yes, you can use other tube sets but it is an alternative.