[Cognomen]

Received Amperex 6AM5 LDIII driver tubes today. Three datasheets I consulted indicated nothing should be connected to pin 6. The pinout is g1, k, h, h, a, pin 6 internal connection do not connect to anything, g2. While looking at the tube with a hand lens, however, I noticed that pin 6 does not connect to anything inside the tube. Shall I clip pin 6 or can I probably deploy it in EF91/92 mode in the Ld III without clipping the pin without risking a problem? At the bottom of the tube, pin 6 is about 1-2 mm away from two rods that seem like they probably run up the tube under its "full surround internal shield/canister." One of them terminates after that toward the top of the tube with a connection to the the getter. The other has no terminal connection up there above the canister/shield. I have no idea what happens to the rods inside the shield/canister or whether they are continuous or not.

 

[CheggStudyTools]

New favourite opamp/tube combo after some heavy testing.

Check https://www.head-fi.org/showcase/burson-audio-supreme-sound-opamp-v6-vivid-and-classic.23186/reviews for details.

I saw your post on the other thread talking about needing adapters for the 6ES8 and I'm attempting to get the parts for myself, do you know where you got them or where I can look?

 

[barbazz]

I saw your post on the other thread talking about needing adapters for the 6ES8 and I'm attempting to get the parts for myself, do you know where you got them or where I can look?

The 6ES8 has the same pinout as 6DJ8, so, if you want to build your own adapter, you can check this post for great step-by-step instructions: https://www.head-fi.org/threads/how...le-triode-tubes-with-little-dot-mk-ii.686893/

Another option is to buy a pre-made one. Fellow Head-Fier @Deyan can assist you with that. I bought mine from him and I really could not recommend it enough. Very high quality and great service. Check some examples here: https://www.head-fi.org/classifieds/custom-tube-socket-adapters.11214/

 

[CheggStudyTools]

The 6ES8 has the same pinout as 6DJ8, so, if you want to build your own adapter, you can check this post for great step-by-step instructions: https://www.head-fi.org/threads/how...le-triode-tubes-with-little-dot-mk-ii.686893/

Another option is to buy a pre-made one. Fellow Head-Fier @Deyan can assist you with that. I bought mine from him and I really could not recommend it enough. Very high quality and great service. Check some examples here: https://www.head-fi.org/classifieds/custom-tube-socket-adapters.11214/

Thanks so much for pointing me in the right direction, I've made the decision to start with the LME49720NA's and 6Zh1P-ЕV for its lower price point, but will still be looking at the V6 + RCA down the road once I get more comfortable with tubes. I know in your review of the V6 that it made the LD1+ sound completely different, and I'm assuming you now prefer that to your original #1, if you were to draw comparisons for each, what about the V6 + RCA stood out to you that made you change your mind?

 

[barbazz]

I've made the decision to start with the LME49720NA's and 6Zh1P-ЕV

That's a great combo to start your tube (and opamp) rolling adventure.

The biggest difference I noted with the Vivid was definitely the soundstage, while the 6ES8 brought the full and rich textures you would expect with tubes.

I did try the Vivid with the Voshkods and the difference from the LME49720 was marginal. The 6ES8 with the LME49720 was OK; the textures were there, but I missed some detail. The combo of Burson's detail and imaging and the "tube sound" of 6ES8 made the difference.

My current top 5 (all with Burson V6 Vivid):

• RCA 6ES8 (Mullard)
• Mullard M8083
• Elektronska Industrija 6HM5
• Novosibirsk 6S2S
• JJ E88CC

Also, keep in mind that there are several versions of the RCA 6ES8. Mine was made by Mullard, but I've seen others with Made in Holland (made by Philips) and Made in Germany (probably made by Telefunken) markings.

Finally, this is a case where the journey definitely matters more than the destination. Try new tubes, new opamps, new combos. It's always a joy to hear, even if sometimes subtle, all the differences they bring in.

 

[barbazz]

A quick correction after checking my notes. I haven't heard the RCA 6ES8 with LME49720. It was with MUSES8820, but my remarks remain.

 

[CheggStudyTools]

That's a great combo to start your tube (and opamp) rolling adventure.

The biggest difference I noted with the Vivid was definitely the soundstage, while the 6ES8 brought the full and rich textures you would expect with tubes.

I did try the Vivid with the Voshkods and the difference from the LME49720 was marginal. The 6ES8 with the LME49720 was OK; the textures were there, but I missed some detail. The combo of Burson's detail and imaging and the "tube sound" of 6ES8 made the difference.

My current top 5 (all with Burson V6 Vivid):

• RCA 6ES8 (Mullard)
• Mullard M8083
• Elektronska Industrija 6HM5
• Novosibirsk 6S2S
• JJ E88CC

Also, keep in mind that there are several versions of the RCA 6ES8. Mine was made by Mullard, but I've seen others with Made in Holland (made by Philips) and Made in Germany (probably made by Telefunken) markings.

Finally, this is a case where the journey definitely matters more than the destination. Try new tubes, new opamps, new combos. It's always a joy to hear, even if sometimes subtle, all the differences they bring in.

Got it, I finally took in the LD1+ and have the Voshkod + National Semiconductor setup, I have noticed however that there's a light buzzing/humming in the background. This is more of a general tube amp question since I'm new, but I think I've been able to isolate it to EMF interference from the wireless devices I have around the amp. Would it be possible to cover the tubes in something like a Faraday cage to block it out properly? It also seems it also has a fairly high noise floor as cranking it a little will introduce a decent amount of static sound.

 

[barbazz]

Do you have that buzzing/humming only with the Voskhods? My first pair (I bought them knowing they were in used condition) had a horrible humming, much more pronounced than any other tube I had at the time. I ended up buying a new NOS pair, and the humming disappeared.

 

[mordy]

Do you have that buzzing/humming only with the Voskhods? My first pair (I bought them knowing they were in used condition) had a horrible humming, much more pronounced than any other tube I had at the time. I ended up buying a new NOS pair, and the humming disappeared.

If there is a horrible hum traceable to the tubes they are defective and you should get a refund or replacement.

 

[barbazz]

If there is a horrible hum traceable to the tubes they are defective and you should get a refund or replacement.

Well, in my case, the vendor stated that they were used and could not guarantee proper functioning. It was a long shot that has not worked out so well. Since then, I have only bought NOS tubes with the original box or, in some cases, without the box but coming from bulk stocks. Part of learning, I guess.

 

[CheggStudyTools]

Do you have that buzzing/humming only with the Voskhods? My first pair (I bought them knowing they were in used condition) had a horrible humming, much more pronounced than any other tube I had at the time. I ended up buying a new NOS pair, and the humming disappeared.

I also have a used set of used ge jan5654w that I tossed in for comparison, the noise is LESS, but it's still there. I built myself an EMF shield made out of EMF fabric and covered the tubes, isolating all of the wireless signals I have around me, and have narrowed the problem to two sources:

1) The DAC + laptop, up the chain, which is an E10k (after doing some reading it seems that an E10k + laptop combo causes some grounding issues and leads to humming (?)). But that begs the question of why my previous amp, an Atom amp, didn't have this issue.

2) My cable, and this one's actually super weird. When I physically move my cable up and down in front of me there will be more/less humming. Is this a case of the cable catching EMF? On my Atom amp setup, this has never happened before. I can't find anything online to read up on.

I also unplugged the E10k from the LD1+'s RCA input, and the humming for the most part stopped, leading me to think it would be the E10k, but a tiny amount of humming is still there and I'm unsure if that's the cable. If I crank the amp the static is still there but I'm chalking it up to the noise floor and that's the least of my concerns right now.

I'm genuinely at a loss here. I know these are just growing pains with learning, but it's really throwing me for a loop and I feel very very stupid.

 

[mordy]

I also have a used set of used ge jan5654w that I tossed in for comparison, the noise is LESS, but it's still there. I built myself an EMF shield made out of EMF fabric and covered the tubes, isolating all of the wireless signals I have around me, and have narrowed the problem to two sources:

1) The DAC + laptop, up the chain, which is an E10k (after doing some reading it seems that an E10k + laptop combo causes some grounding issues and leads to humming (?)). But that begs the question of why my previous amp, an Atom amp, didn't have this issue.

2) My cable, and this one's actually super weird. When I physically move my cable up and down in front of me there will be more/less humming. Is this a case of the cable catching EMF? On my Atom amp setup, this has never happened before. I can't find anything online to read up on.

I also unplugged the E10k from the LD1+'s RCA input, and the humming for the most part stopped, leading me to think it would be the E10k, but a tiny amount of humming is still there and I'm unsure if that's the cable. If I crank the amp the static is still there but I'm chalking it up to the noise floor and that's the least of my concerns right now.

I'm genuinely at a loss here. I know these are just growing pains with learning, but it's really throwing me for a loop and I feel very very stupid.

Don’t feel stupid about the hum. There is an audiophile proverb that says:
If they make it, it hums.
Many times it is difficult to pinpoint the source of the hum. Before the cell phones became landlines portable phones were often the culprit.
You can try different electrical outlets and if possible move the amp further away from laptops etc.
Recently I upgraded my PC and now, using the same USB cable, I have much more hum than before - haven’t been able to figure out a fix yet.

 

[mordy]

Well, in my case, the vendor stated that they were used and could not guarantee proper functioning. It was a long shot that has not worked out so well. Since then, I have only bought NOS tubes with the original box or, in some cases, without the box but coming from bulk stocks. Part of learning, I guess.

When I buy (very often used) tubes, I usually go through eBay, using PayPal with a credit card. That way I have three layers of protection.
Only had to fight for a refund once when the US customs lost a pair of tubes. In this case the seller did nothing wrong, but PayPal refunded me.

 

[CheggStudyTools]

Don’t feel stupid about the hum. There is an audiophile proverb that says:
If they make it, it hums.
Many times it is difficult to pinpoint the source of the hum. Before the cell phones became landlines portable phones were often the culprit.
You can try different electrical outlets and if possible move the amp further away from laptops etc.
Recently I upgraded my PC and now, using the same USB cable, I have much more hum than before - haven’t been able to figure out a fix yet.

I connected the back of the amp to a metal radiator grille, the hum remains, unfortunately, so the next step is going up the chain I guess, it could be time to get a new DAC.

Edit: I can break down the static + hum into two sounds- the hum is at 1khz, which I think has a good chance of it being USB interference (I have no idea how to cheaply solve this one) and the static is a constant buzz, which could be dirty power.

 

[mordy]

I connected the back of the amp to a metal radiator grille, the hum remains, unfortunately, so the next step is going up the chain I guess, it could be time to get a new DAC.

Edit: I can break down the static + hum into two sounds- the hum is at 1khz, which I think has a good chance of it being USB interference (I have no idea how to cheaply solve this one) and the static is a constant buzz, which could be dirty power.

Since I have a similar problem I checked on YouTube and found a video that said to try a USB isolator. These devices plug in in front of the USB cable and aren’t that expensive. Judging from Amazon reviews the results are mixed and only around half the people are happy with them.
Someone else suggested a Ferrite choke. These are inexpensive little devices that clamp on the cable - don’t know if they work.
For the AC power you can buy an isolation transformer but these are more expensive and I don’t know how well they work in very case.
In my case I can reduce the hum to inaudible levels by adjusting the volume controls on both my amp and preamp, but the hum is still there when I turn up the volume to levels that are too high to listen to. And being obsessive it annoys me lol…