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Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 174

post #2596 of 7208
Quote:
Originally Posted by mordy View Post

Welcome to the forum KR500!

 

Presently I do most of my listening through speakers, but I do have the Audio Technica ATH AD700 headphones (same as your old ones). Truth is that my speakers have better resolution than my ATH AD700 headphones.

 

One reason I like the AT phones is that they are very comfortable to wear (and don't laugh!) they don't make my ears feel hot. A few years ago I had a set of Sennheiser HD600, but I could not wear them for a long time because they made my ears too hot and uncomfortable, and I felt that they contributed to earwax buildup.

 

Are the ATH - AD900X headphones as comfortable as the AD700? I read good things about them in Stereophile magazine.

 

I am thinking of getting a better set of headphones, moderately priced of course, and would appreciate suggestions. Light weight and comfort are important to me, as well as the sound.

 



I love my AD900x, its great for the price! I pretty good upgrade over the AD700.

post #2597 of 7208
RCA 6HZ6 and 6DT6/A
 

 

 

I am unable to discern any sonic differences between these two tubes. Mim Grey's voice is delicious, warm and full; the bass is satisfyingly deep, punchy and clean; and the highs are well detailed with a nice bit of sparkle. Further, the sound stage is exceptionally wide and instrument separation is excellent. In my experience, everything Mordy writes about the 6DT6 is also true about the 6HZ6 in my possession.
 
That said, I prefer the 6DT6/A only for the fact that it runs cooler. The 6HZ6 runs quite hot, so unless the extra gain .45amp heaters might provide is important in your setup, I recommend the 6DT6/A over the 6HZ6. 
post #2598 of 7208
Quote:
Originally Posted by TrollDragon View Post

Here are the 6BY6's

 

 

I put the pair in with the round Getter and have been listening to The Best of Acoustic by Jethro Tull and I am absolutely amazed at how much better these sound over the stock GE5654's.

 

There is actually some Bass in this amp now! When I first set it up I was missing the Bass that my SS amp provided, but now this is impressive.

 

Are there any other tubes with a nice deep clean Bass response?

 

A very easy recommendation is any EH90 manufactured by Philips. These tubes might have any number of brand names printed on the glass, Philips, of course, and also Mullard, Valvo, Siemens and perhaps others as well. This is a top tier tube in every way, with especially excellent bass. If you search this forum, you will find very strong endorsements of this tube by Hynos1 and Audiofanboy.

 

What you are looking for is a tube with smooth dark gray plates and rather large tall holes. For example:

 

http://www.ebay.com/itm/Mullard-EH90-Valves-/171004688579?pt=UK_Sound_Vision_Valves_Vacuum_Tubes&hash=item27d0ac78c3

 

http://www.ebay.com/itm/EH90-EH-90-6CS6-VALVO-NOS-NEW-MCINTOSH-/221267124842?pt=DE_TV_Video_Audio_Elektronenr%C3%B6hren_Valves&hash=item33848c626a

 

http://www.ebay.com/itm/1x-EH90-6CS6-PHILIPS-NOS-BRITISH-Tube-Rohre-Lampe-TSF-Valvola-Valvula-/260873874189?pt=Vintage_Electronics_R2&hash=item3cbd4b6b0d

 

http://www.ebay.com/itm/1-neue-Rohre-Siemens-EH90-mit-originaler-Box-U58-/380558649752?pt=R%C3%B6hren&hash=item589b102998

 

(I have selected these to give suitable examples. I am not suggesting that any of these is a good deal....)

 

Happy hunting!! :)

 

Edit: Oh, another tube with great bass is the RCA 6DT6! :)


Edited by gibosi - 8/27/13 at 9:08pm
post #2599 of 7208
Quote:
Originally Posted by gibosi View Post

 

A very easy recommendation is any EH90 manufactured by Philips. These tubes might have any number of brand names printed on the glass, Philips, of course, and also Mullard, Valvo, Siemens and perhaps others as well. This is a top tier tube in every way, with especially excellent bass. If you search this forum, you will find very strong endorsements of this tube by Hynos1 and Audiofanboy.

 

What you are looking for is a tube with smooth dark gray plates and rather large tall holes. For example:


Edit: Oh, another tube with great bass is the RCA 6DT6! :)

Thanks gibosi!

 

I really appreciate all the links so I know what to look for, those EH90's are pricy, so I'll have to keep a watch out for a deal on some... :)

 

The 6DT6's on the other hand are very reasonable! :)

 

Are the Haltron 6CS6 from Japan on par with the EH90's you linked?

post #2600 of 7208

Alright! Finally back in my -primary- country, and almost back in the game now that I have my amp back; if it weren't for the fact that I'm soooooo tired...! Jetlag is one the thing I just can never get used to even after traveling for most of my life...

 

But fear not, I will end up giving those final impressions on Belgian and UK EH90 tubes. I just strapped the tubes back in and am warming the amp up for a good listen (tried it last night but almost fell asleep after three tracks, seriously; then again, I hadn't slept for 30h...).

 

Philips group EH90 tubes aren't particularly expensive if you pick odd-labeled ones. There's like an unlimited number of brands you can pick from too (Philips, Mullard, Siemens, Miniwatt, Mazda, Adzam, Valvo, Pope...). Btw, Adzam tubes will almost certainly be the same Belgian M.B.L.E. tubes I'm testing, whereas the other brands like Siemens would be 70-80% Mullards, 10-20% M.B.L.E., 0-10% Misc or mostly Mullards anyway. I have yet to find or see Holland-made EH90 tubes.

post #2601 of 7208

Thanks Audiofanboy!

 

I will patiently wait out some Phillips type EH90's on eBay, I am enjoying the 6BY6's right now so there is no rush.

beerchug.gif

post #2602 of 7208

I've noticed gibosi mention the gain of various tubes in past messages and I have looked at the spec sheet's but the gain is not specifically listed. Is this a value that has to be calculated?

I am going to have to dig up some "Tubes for Dummies" PDF's off the net and do a little reading. cool.gif

post #2603 of 7208
Quote:

Are the ATH - AD900X headphones as comfortable as the AD700?

Mordy;

 

In a nutshell , yes plus improved pads and nice bass presence, which was a bit too lean in the ATH AD-700's.

General construction is a step up other than the plug end .

I think the drivers are better than the 700's although still breaking in at about 25 hours so far

Comfort and ear ventilation is the major reason I wanted to stay in the AT family.

I have excellent full range speakers and a class A SET amp for non headphone listening .

Since the missus is 64 she doesn't necessarily want to hear some types of music in the evening that I do... so the Little Dot works out great while she is chillaxin' with a book or crossword puzzle. Plus in August with fans and AC going it's a little more noise isolation

Sorry to drift off OP topic some here but I'll post my impressions of trying the Mullard EF92's when I get them next month. They will be my first excursion out of standard EF95 territory with the LD amp

post #2604 of 7208
Quote:
Originally Posted by TrollDragon View Post

I've noticed gibosi mention the gain of various tubes in past messages and I have looked at the spec sheet's but the gain is not specifically listed. Is this a value that has to be calculated?

I am going to have to dig up some "Tubes for Dummies" PDF's off the net and do a little reading. cool.gif

 

Not quite.

 

Gain or mu is very hard to calculate for pentode/heptodes -non-triodes basically- as it would vary depending on a number of factors. So, it isn't used or usually given for those tubes. A value is sometimes mentioned for cases where the tube (the pentode) or part of the tube (for a heptode) are used in a triode-like way.

 

It's essentially the voltage gain in a tube. A 6AK5 driver tube (triode-strapped) has a mu of 20, which voltage out is 20x higher than voltage in. Gain is typically used for triodes, or when pentodes are triode-strapped (which is why gibosi, myself or google can give you a mu for, say, a 6AK5 or 6AU6 pentode), but is usually only mentioned in triode datasheets or for pentodes with known triode applications, such as a 6AK5.

 

Yeah, you'll probably want to do at least some degree of "tube for dummies" or "tube basics" reading at some point. None of it will make sense right away, but it'll help you understand things little by little, and will eventually sink in and allow you to understand just what it is that goes on in there! I know I read a whole bunch of stuff in the last year or so, and all of it took months for me to really "get" and start using.

post #2605 of 7208
Quote:
Originally Posted by Audiofanboy View Post

Alright! Finally back in my -primary- country, and almost back in the game now that I have my amp back; if it weren't for the fact that I'm soooooo tired...! Jetlag is one the thing I just can never get used to even after traveling for most of my life...

 

But fear not, I will end up giving those final impressions on Belgian and UK EH90 tubes. I just strapped the tubes back in and am warming the amp up for a good listen (tried it last night but almost fell asleep after three tracks, seriously; then again, I hadn't slept for 30h...).

 

Philips group EH90 tubes aren't particularly expensive if you pick odd-labeled ones. There's like an unlimited number of brands you can pick from too (Philips, Mullard, Siemens, Miniwatt, Mazda, Adzam, Valvo, Pope...). Btw, Adzam tubes will almost certainly be the same Belgian M.B.L.E. tubes I'm testing, whereas the other brands like Siemens would be 70-80% Mullards, 10-20% M.B.L.E., 0-10% Misc or mostly Mullards anyway. I have yet to find or see Holland-made EH90 tubes.

I have the Valvo variant which has amazing 3d imaging, instrument separation could be better but still acceptable.

 

this is with a 2-7 strap, I'm going to try the 1-7 strap this week as well to compare.

post #2606 of 7208
Quote:
Originally Posted by TrollDragon View Post

Are the Haltron 6CS6 from Japan on par with the EH90's you linked?

 

To the best of my knowledge, Haltron did not manufacture tubes. They merely purchased tubes, probably the cheapest deal they could find, and relabeled them for sale under their own brand. So it often takes a bit of sleuthing to figure out which company manufactured a particular Haltron tube. In the case of a Haltron 6CS6 made in Japan, I have no experience with this tube and don't recall anyone posting anything. Maybe one of our lurkers has this tube and would be willing to give us some feedback. :)

post #2607 of 7208
How long do new tubes take to burn in got some mullards but they don't sound as good as the stock tubes from my little dot mk3 amp. I know a burn in is required just curious.
post #2608 of 7208
Quote:
Originally Posted by foreign View Post

How long do new tubes take to burn in got some mullards but they don't sound as good as the stock tubes from my little dot mk3 amp. I know a burn in is required just curious.

 

I typically burn tubes in for 20 to 30 hours. However, some tubes appear to take longer, as much as 50 hours, or more, to finally stabilize.

post #2609 of 7208
Quote:
Originally Posted by Audiofanboy View Post

 

Not quite.

 

Gain or mu is very hard to calculate for pentode/heptodes -non-triodes basically- as it would vary depending on a number of factors. So, it isn't used or usually given for those tubes. A value is sometimes mentioned for cases where the tube (the pentode) or part of the tube (for a heptode) are used in a triode-like way.

 

It's essentially the voltage gain in a tube. A 6AK5 driver tube (triode-strapped) has a mu of 20, which voltage out is 20x higher than voltage in. Gain is typically used for triodes, or when pentodes are triode-strapped (which is why gibosi, myself or google can give you a mu for, say, a 6AK5 or 6AU6 pentode), but is usually only mentioned in triode datasheets or for pentodes with known triode applications, such as a 6AK5.

 

Yeah, you'll probably want to do at least some degree of "tube for dummies" or "tube basics" reading at some point. None of it will make sense right away, but it'll help you understand things little by little, and will eventually sink in and allow you to understand just what it is that goes on in there! I know I read a whole bunch of stuff in the last year or so, and all of it took months for me to really "get" and start using.

Thanks, l will do some reading for sure, at least get some basics down.

 

Quote:
Originally Posted by gibosi View Post

 

To the best of my knowledge, Haltron did not manufacture tubes. They merely purchased tubes, probably the cheapest deal they could find, and relabeled them for sale under their own brand. So it often takes a bit of sleuthing to figure out which company manufactured a particular Haltron tube. In the case of a Haltron 6CS6 made in Japan, I have no experience with this tube and don't recall anyone posting anything. Maybe one of our lurkers has this tube and would be willing to give us some feedback. :)

Thanks, they were for sale fairly cheap, which was the reason I asked.

post #2610 of 7208

Hi KR500,

 

Your post made me laugh - my wife is the same age and she thoroughly dislikes my musical taste (20's classic jazz). My solution is to close the door to my man cave and crank up the volume.

 

However, sometimes i have family members or guests over, and then I have to resort to the headphones which I find less satisfying. Was able to buy the ATH AD700 as B stock for $65 a few years ago. The best price I could find on the ATH AD900X is around $190 which is a drop high - looking for a better deal.

 

About tubes I find it fascinating that some European vendors seem to think that US made stuff is the best, and some Americans seem to think that the European stuff is the best.

 

Dollar for dollar the best current deal is RCA 6DT6/6DT6A (1/7 strap). The more I listen to them, the more I like them. Go Detox!
 

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