[ViperGeek]

  Hi Dave,
 
When we write BGRP, we mean "black glass round plates". Meaning the tubes glass is black and the plates (anodes) are round.
You can see it in this pic:

You see those two round grey plates above.
 
Down below you see the 6C8G version of TS BGRP.

 
Thanks for the acronym expansion and sample pictures!  They're very much appreciated.
 
So, if I'm scouring the ol' interwebs for these, will the description state "black glass" and/or "round plate", or must I ask the average eBay'er for this level of detail?
 
- Dave

 

[SonicTrance]

You should be able to tell from the pics if not advertised in the auction. It's great if you can learn how the different constructions look. That way you can do bargains when the seller doesn't know what he got.

 

[baronbeehive]

   
...........
Since my last post, I've also picked up a quad of NOS RCA 6AS7G from the mid 50's.  Initially (to my ear), the difference in power tubes was much more subtle than the difference from rolling driver tubes.  But what I've notice over a dozen hours of listening is that I'm more willing to crank up the volume than I was with the stock power tubes.  I've been told that the brain confuses harshness with loudness, and if that's true, then the 6AS7G's are much, much smoother and "analog" than the stock tubes, which IMO is an awesome improvement.
 
Thanks again for taking the time to swing by this old thread and help a new LD fan.
 
- Dave

 
Glad to help, we were noobs once! That's absolutely right about the smoothness of the RCA's which you  noticed, quite subtle but very much more musical. Driver tubes are much more noticeable than power tubes in terms of sound. For example if you want a warm sound go for the RCA power tubes and then tweek that with the driver tubes depending on what sound you want.
 

   
Thanks for the acronym expansion and sample pictures!  They're very much appreciated.
 
So, if I'm scouring the ol' interwebs for these, will the description state "black glass" and/or "round plate", or must I ask the average eBay'er for this level of detail?
 
- Dave

 
 

You should be able to tell from the pics if not advertised in the auction. It's great if you can learn how the different constructions look. That way you can do bargains when the seller doesn't know what he got.

 
As SonicTrance says the best way is to look at the pictures in close up on ebay and you will soon be able to tell the difference between black glass round plate or flat plate, or "t" plate, or tall glass or short glass, or short base or long base etc., just by looking although it will usually be in the description.
 
Similarly GT, GTA, GTB or other designations all denote slightly different things such as plate voltage, or VT231 which are military versions of 6SN7's.
 
All things which you can pick up fairly easily

.

 

[ViperGeek]

Thanks again for the informative and friendly replies.  I was able to find BGRP's on eBay (there's even a dedicated /bhp URL):
 
http://www.ebay.com/bhp/tung-sol-round-plate
 
I hadn't realized how expensive these vintage NOS tubes were.  I'll have to groove to my "NNS" Tung-Sol and CV181-Z driver tubes for a little while longer while I save my pennies.
 
Why is the best-sounding stuff always the most expensive?  (Yes, that's a rhetorical question).
 
Roll on!
 
- Dave

 

[ViperGeek]

I have a related question regarding 6SL7/6SN7 driver tube usage in the Little Dot MK VI+.
 
I noticed my bookmarks have a slightly uneven mix of the two, with the 6SN7 being more common (again, in my bookmarks).  During my research of the differences between the high mu (70) 6SL7 and medium mu (20) 6SN7, I found multiple instances where "Internet experts" claimed that these are not necessarily interchangeable.
 
Other than a noticeable decrease in volume when swapping out the Tung-Sol 6SL7GTs for the CV181-Zs (6SN7 equivalent), I haven't experienced any problems, What makes the MK VI+ so versatile that it can drive either the high gain 6SL7s or the medium gain 6SN7s without bursting into flames?
 
UPDATE: Further research seems to indicate that, in general, you can replace high gain factor tubes (e.g. 6SL7/ECC35) with lower gain factor tubes (e.g. 6SN7/ECC32), but not the other way around.  Since the PDF for the Little Dot MK VI+ states "Can be replaced with ECC35 (confirmed)", I suspect reason we can use 6SN7s is precisely because lowering the gain factor is safe(r) than raising it.
 
- Dave

 

[goreshade]

Is the MK 6+ suitable for k701 ? I've heard some people said that the SE output on mk 6+ is noisy. Is that true ?
 
Has anyone tried Mk 9 ? Is it capable of delivering enough current for K701 ?

 

[Sam-Fi]

Is the MK 6+ suitable for k701 ? I've heard some people said that the SE output on mk 6+ is noisy. Is that true ?

Has anyone tried Mk 9 ? Is it [COLOR=545454]capable of delivering enough current for K701 ?[/COLOR]

The mk 9 is great I have the k7xx so they are more like the 712 so, with the slightest looseness on the bass notes compared to your 701, and I have to conclude the 712 and any of the k7xx series run really great with the mk9.

 

[Wolvebain]

I just got my Little Dot mk VI+ a few days ago. And what a beauty!
 
Still stock tubes, but looking to upgrade [suggestions welcomed] I'm in South Africa, and am looking for tubes that can be shipped to me via expedited shipping [Fedex/DHL/etc]
 
My headphones are:

1. HD650
2. Q701 [bass-port and balanced modded]
3. HD800S [recent purchase]
4. HE-560 [recent purchase, to arrive soon]

 
The HD650 & Q701 will prob be on their way out, in favor of the newer HD800S & HE-560.
 
HD800S impression on the stock tubes are not bad; good sound stage, nice mids, but bright and very lean bass.

 

[ViperGeek]

  I just got my Little Dot mk VI+ a few days ago. And what a beauty!
 
Still stock tubes, but looking to upgrade [suggestions welcomed] I'm in South Africa, and am looking for tubes that can be shipped to me via expedited shipping [Fedex/DHL/etc]
 
My headphones are:

1. HD650
2. Q701 [bass-port and balanced modded]
3. HD800S [recent purchase]
4. HE-560 [recent purchase, to arrive soon]

 
The HD650 & Q701 will prob be on their way out, in favor of the newer HD800S & HE-560.
 
HD800S impression on the stock tubes are not bad; good sound stage, nice mids, but bright and very lean bass.

 
Hi Wolvebain.
 
If you scroll up a few pages to my initial inquiry about tubes for the MK VI+:
 
http://www.head-fi.org/t/522099/little-dot-mk-vi-little-dot-mk-viii-se-owners-unite/2235#post_12203881
 
there have been lots of great advice shared by the seasoned experts about the various tube rolling options for our beloved Little Dot.  Additionally, my personal opinion on warmer, smoother power tubes was shared here:
 
http://www.head-fi.org/t/522099/little-dot-mk-vi-little-dot-mk-viii-se-owners-unite/2265#post_12360616
 
"Since my last post, I've also picked up a quad of NOS RCA 6AS7G from the mid 50's.  Initially (to my ear), the difference in power tubes was much more subtle than the difference from rolling driver tubes.  But what I've notice over a dozen hours of listening is that I'm more willing to crank up the volume than I was with the stock power tubes.  I've been told that the brain confuses harshness with loudness, and if that's true, then the 6AS7G's are much, much smoother and "analog" than the stock tubes, which IMO is an awesome improvement."
 
I'd look to consider rolling some 6SN7-family driver tubes and NOS RCA 6AS7G power tubes to mellow out your HD800S's and see how you like it.  IMO, driver tubes make the biggest difference, but as I quoted above, the NOS RCA power tubes really mellowed any perceived harshness I had experienced.
 
- Dave

 

[Wolvebain]

Thanks Dave.
 
I have read your posts regarding the RCA 6AS7G power tubes... Very helpful, and has caused me to hunt these tubes
You are spot-on with me wanting to 'mellow out' the brightness of the HD800S, and wanting to add more bottom-end to them.
 
I've been corresponding with Brent from AudioTubes.com on a quad matched set of RCA 6AS7G.  I hope he has stock of some NOS.
Unfortunately, the only ship via USPS EMS express, and if I'm lucky, may only get them within 4 weeks from collection/drop-off
 
If you can suggest other places I may source the NOS RCA 6AS7G power tubes from, I'd be very grateful.  [ looking at the shipping option of the https://tubedepot.com/products/6sl7gt-rca now ]

 

[Wolvebain]

I just purchased these quad matched NOS RCA 6AS7G from eBay:
http://www.ebay.com/itm/322090983219
 
Hope they are a good buy, as I had to pay a lot for shipping...
 
What do you say?

 

[ViperGeek]

  I just purchased these quad matched NOS RCA 6AS7G from eBay:
http://www.ebay.com/itm/322090983219
 
Hope they are a good buy, as I had to pay a lot for shipping...
 
What do you say?

 
As long as they're matched and still have some life left, I think you made a good purchase.  I bought mine off of eBay too:
 
http://www.ebay.com/itm/252252178741
 
- Dave

 

[Wolvebain]

Thanks @ViperGeek; much appreciated bud.
 
I was considering going for the Bendix 6080, but at USD.175 a pop, it was getting a bit too hectic for my taste
 
I see  you mentioned the Shuguang Treasure CV181-Z pre-amp tubes, which is a 6SN7 tube and not a 6SL7 which the manual says is a viable replacement for the 6H9C.
I assume from your posts that they work, and work well. 
 
Should I get a matched pair, like these: Shuguang Treasure CV181-Z Vacuum tube pair Collection Version
 
6SN7
Or should I get one of the below pairs instead?

1. 6SU7GTY Tung Sol USA military stock $199.00 per pair [ www.audiotubes.com ]
2. 6SL7WGT Sylvania made brownbase $80.00 per pair [ www.audiotubes.com ]
3. 5691 RCA redbase, $160.00 per pair [ www.audiotubes.com ]
4. 6SL7GT RCA

 

[ViperGeek]

  Thanks @ViperGeek; much appreciated bud.
 
I was considering going for the Bendix 6080, but at USD.175 a pop, it was getting a bit too hectic for my taste
 
I see  you mentioned the Shuguang Treasure CV181-Z pre-amp tubes, which is a 6SN7 tube and not a 6SL7 which the manual says is a viable replacement for the 6H9C.
I assume from your posts that they work, and work well. 
 
Should I get a matched pair, like these: Shuguang Treasure CV181-Z Vacuum tube pair Collection Version
 
6SN7
Or should I get one of the below pairs instead?

1. 6SU7GTY Tung Sol USA military stock $199.00 per pair [ www.audiotubes.com ]
2. 6SL7WGT Sylvania made brownbase $80.00 per pair [ www.audiotubes.com ]
3. 5691 RCA redbase, $160.00 per pair [ www.audiotubes.com ]
4. 6SL7GT RCA

 
I'm glad I can pay back some of the knowledge and experience I gained from this 153-page, 2294-post thread. 

 
Yes, the 6SN7-like CV181-Z's work great in my system.  Due to their width, they require socket savers to fit.  They also lower the output volume for a given knob position slightly, but since I've always had plenty of ear-splitting volume left on the dial, this has never been a problem for me.  And even if it were, the Gain Control DIP switches inside can boost the output even further.
 
While I love my Shuguang Treasure driver tubes, others on this thread have preferred other options (RCA NOS, Tung Sol, etc.).  I will say that the Tung Sol 6SN7GT's are on my short list, but I'll have to rob a bank to afford them.
 
I'd roll one tube at a time, enjoy the post-burn-in delight for a while, then try a different set of driver tubes and see what you like best.  Drivers do make the biggest difference, so you should be able to tell pretty quickly (after burn-in) which sound you prefer.  Or perhaps you'll end up rolling different tubes for different cans.
 
Have fun!
 
- Dave
 
ps. I obtained my CV181-Z's straight from Psvane:
 
     http://psvanetube.com/wordpress/store/products/cv181-z-pair/ 
 
     This may be an authorized North American regional seller though, but I'd be cautious when dealing with unauthorized third party resellers.

 

[Wolvebain]

Thanks for the info bud...
 
I have been checking out the Psvane CV181-T Mark II's as they seem to have a better bottom end, and reduce the brightness of too bright set-ups... which is really appealing for my set-up.
 
Link #1: http://www.amazon.com/Matched-Psvane-CV181-T-Premium-Treasure/dp/B00N4L28HK
Link #2: http://psvanetube.com/wordpress/store/products/cv181-tii-pair/
 
Think I should pull the trigger?
 
Now.. to find some 8pin to 8pin  socket savers that are black or bronze/gold color