[baronbeehive]

I am a big fan of NOS Mullard tubes, but that one has a different pin out, do you have adaptors?
If you go that way let us know how it compares.

There don't appear to be adapters. Just as well I don't know if pentodes and twin triodes are compatible, so unless anyone knows differently I won't be using the EL84's as drivers. I'm still debating whether to try the Mullards in the power stage, not sure about their sound as power tubes.

 

[Mecii]

Just got my unit back today! Arrived cold so I let it sit un powered in my office while I finish my shift at work, don't want to start it cold



So I also installed my Russian Power Tubes [the previous Flavor of the Month lol] an I'll fire up my 12sn7 along with it here in the next 2 hours or so!
Other wise Cliff the gentleman who performed the mods did an excellent job! An I'm excited to hear it, I also just got a silver cable for my HD 800 so it should be a pretty big improvement over the last time I listened[/QUO

Trying to track down a place to purchase the Audio Note caps. Can you tell me where you purchased yours from or where I might be able to purchase these?
Thank you.

Maybe the others will know for the US, in Europe we usually use HiFiCollective.

Well it seem this is a popular little cap since so far every place that carries these are on back order. Is there a substitute cap that would work in place of the KAISEI that is the same or better quality?

 

[Peekeesh]

Just curious, if you replace the power tubes with something bigger and more powerful, will that give you more juice to drive some power hungry headphones?

 

[DavidK35]

Just curious, if you replace the power tubes with something bigger and more powerful, will that give you more juice to drive some power hungry headphones?

There is a limit to what you can run. Personally I would not go over 0.9A current draw. That still leaves a lot of choices,
6L6G or 6BG6G for example. Seriously you would not want to go bigger than that, not practical,the amplifier is the limiting factor.

 

[Peekeesh]

There is a limit to what you can run. Personally I would not go over 0.9A current draw. That still leaves a lot of choices,
6L6G or 6BG6G for example. Seriously you would not want to go bigger than that, not practical,the amplifier is the limiting factor.

Is this good?

https://tubedepot.com/products/6bg6g-ga

Or do i have to find a specific brand?

also, do i need some sort of adapter for the 6bg6g?

 

[baronbeehive]

I'm not sure but it looks like your amp has been discontinued, my speaker version has been upgraded a while ago, don't know what you guys think about that.

 

[DavidK35]

I'm not sure but it looks like your amp has been discontinued, my speaker version has been upgraded a while ago, don't know what you guys think about that.

Sad, but nothing lasts forever. Don't know but looks like the replacement is this with usb & some obscure 7 & 9 pin tubes:

https://www.aliexpress.com/item/GD-...r-Smart-Desktop-Wifi-SD-Card/32811062445.html

Amazon & some dealers on e-bay still have the original. Better hurry if anyone is thinking about buying it.

 

[DavidK35]

Is this good?

https://tubedepot.com/products/6bg6g-ga

Or do i have to find a specific brand?

also, do i need some sort of adapter for the 6bg6g?

Yes, those tubes are fine. You will need to go to e-bay & look up tube adaptors for 6BG6G. The G version tubes are worth seeking out
over the GA type.

 

[baronbeehive]

Sad, but nothing lasts forever. Don't know but looks like the replacement is this with usb & some obscure 7 & 9 pin tubes:

https://www.aliexpress.com/item/GD-...r-Smart-Desktop-Wifi-SD-Card/32811062445.html

Amazon & some dealers on e-bay still have the original. Better hurry if anyone is thinking about buying it.

Yes!

There's also this high end model:

https://www.amazon.co.uk/Nobsound-R...1?ie=UTF8&qid=1533235090&sr=8-1&keywords=appj

.... the replacement for mine:

https://www.amazon.co.uk/PA1501A-6A...2?ie=UTF8&qid=1533235090&sr=8-2&keywords=appj

... and this rather odd looking one:

https://www.amazon.co.uk/Nobsound-V...4?ie=UTF8&qid=1533235090&sr=8-4&keywords=appj

... none of them appear to be headphone amps!

I don't want any of these after perfecting the original with the mods we've done here!! Luckily it looks like the amp is reliable, I've had mine for at least 5 years, but what happens if one of the surface mount parts, or the SMPS goes west?

 

[Pratt99]

For the Philips I was lucky to pay about £30 from a UK seller so no customs charge or VAT, I would try and find something around $60. For the Mazda silver anode I think I paid around $65. I have seen them going for around $75 on Ebay by Brent Jesse who is a reputable seller and sells them on his own website for much more than this. I wouldn't pay silly money, I'm talking hundreds of dollars, just wait for one to come up at a reasonable price and NOS testing.

I would be happy to go for either of these:
https://www.ebay.com/itm/2x-ECC83-1...357459?hash=item41dff6a4d3:g:lUUAAOSwmuVaX6pz

https://www.ebay.com/itm/ECC83-12AX...916737?hash=item2143a6aa01:g:1ZsAAOSw7mpbS3XB

The Philips is one of the better earlier versions from the 1950's and 1960's, with the larger ring getter and has the delta symbol indicating Philips Herleen factory Holland, and is branded Valvo which is the Philips brand for Germany. Mine is branded Mazda.

The Mazda silver anode is the same as the one I've got, there are several versions with different plate construction but I imagine they sound similar.

The Mazda has a wonderful light airy musical sounding treble to die for and a nice tight bass.

The Philips is richer sounding but with incredible extended bass and treble, both very balanced sounding.

They are quite expensive but don't forget if you don't like them you can always resell them.

Let us know how you get on, I would be interested in how they sound on your amp in comparison to mine!

@baronbeehive Thanks much for this info. I have setup some ebay search alerts for these. It is true that it will be easier to resell these in ebay in the case that I don't like coz these are known names in the tube world. My current favourite is telefunkun ( branded as dynaco and fisher) 12ax7 and I got them for 25 dollars. They have a nice flat response, great transparency and goes well with my hd600. Will report back if I manage to buy the Philips or Mazda. Also saving some cash to upgrade my Schiit Bifrost sigma delta to multibit. I believe that should improve resolution from the DAC end.

 

[baronbeehive]

@baronbeehive Thanks much for this info. I have setup some ebay search alerts for these. It is true that it will be easier to resell these in ebay in the case that I don't like coz these are known names in the tube world. My current favourite is telefunkun ( branded as dynaco and fisher) 12ax7 and I got them for 25 dollars. They have a nice flat response, great transparency and goes well with my hd600. Will report back if I manage to buy the Philips or Mazda. Also saving some cash to upgrade my Schiit Bifrost sigma delta to multibit. I believe that should improve resolution from the DAC end.

No problem!

Don't forget to get the type I posted, there are several different types, and brands and the only way you can know it's Philips is the delta symbol which braaam told me about. I've been listening again to mine and decided not to change again for anything else, this tube has everything for me and superb detail for a 12ax7, ECC83 type, maybe because it's a European tube with different sound to some others, also I believe the earlier versions to be the best. I don't know if you'll like it, it's way different type of sound to the Telefunken, which I have to say I didn't like, I don't like neutral tubes usually! Nevertheless it would be interesting to try the Philips with your HD600, I've found it to have the best soundstage of any I've tried. The Mazda is lighter sounding but I can't get rid of this tube as the treble is so good as I've said.

Edit: I think you might get better layering on the soundstage whereas the Tele's would be flatter, though clearer. I found the 12SL7 GE's to be transparent and flat like this but they worked a treat on my other amp which already had good layering.

 

[Rick_B]

I joined this drop. I haven't gotten it yet but massdrop says it will ship mid august.

https://www.massdrop.com/buy/appj-1502a-tube-headphone-amplifier/talk#discussions

How do i determine if I'm going to need bypass caps? what bypass caps would you recommend? Thanks!!




Thanks. I sent the seller a message.

I joined this one, too, and got my amp yesterday...I got shipping notification Wednesday that it was being sent from Hong Kong...arrived here at around 1:00PM local time...two days from Hong Kong to Texas, wow!

I've got it running this morning in my Ham Radio room, listening to my HE-400i's with a MyDAC hooked up to the APPJ with Wireworld Eclipse 8 cables, feeding it from this computer and JRiver via Audioquest Carbon USB cable, and using a home made braided SPC copper braided power cord....installed some NOS Sylvania 6V6GTA "coin base" tubes with a Great Britain manufactured 12AX7 (haven't looked deeply into who makes this one) after running it about an hour with the stock tubes...but, swapped that 12AX7 out just now with a NOS RCA 12AY7 and gained some definition that was glossed over by the previous tube...I've got several other flavors of 6V6 tubes in one of my packed storage units so I'll have to go mining there this weekend...

I think I may like this one better, or at least as much, as my Antique Sound Labs MG-Head OTL MarkIII DT. I'll also need to compare it to my Darkvoice with NOS tubes and my Little Dot with Western Electric 403A tubes and a Burson V5i opamp...

I can't wait to let this thing run in for a couple of weeks, and then start with a few little mods, I have some Black Gate 330mfd@25V caps I'll use for the cathode bypass caps, I'll probably bypass them with a couple of .01mfd Auricaps I have if I don't use Sprague Vitamin Q .012@400V oil caps...I also have some Gudeman .51@300V Vitamin Q type oilers that I may try as coupling caps...

It's all fun and games...

P.S. I like how this site classifies me as a New Head Fi'er after joining over a decade ago! I lurk, I guess, and learn from others and only contribute if I have something salient to say. Glad this forum exists!

 

[baronbeehive]

I joined this one, too, and got my amp yesterday...I got shipping notification Wednesday that it was being sent from Hong Kong...arrived here at around 1:00PM local time...two days from Hong Kong to Texas, wow!

I've got it running this morning in my Ham Radio room, listening to my HE-400i's with a MyDAC hooked up to the APPJ with Wireworld Eclipse 8 cables, feeding it from this computer and JRiver via Audioquest Carbon USB cable, and using a home made braided SPC copper braided power cord....installed some NOS Sylvania 6V6GTA "coin base" tubes with a Great Britain manufactured 12AX7 (haven't looked deeply into who makes this one) after running it about an hour with the stock tubes...but, swapped that 12AX7 out just now with a NOS RCA 12AY7 and gained some definition that was glossed over by the previous tube...I've got several other flavors of 6V6 tubes in one of my packed storage units so I'll have to go mining there this weekend...

I think I may like this one better, or at least as much, as my Antique Sound Labs MG-Head OTL MarkIII DT. I'll also need to compare it to my Darkvoice with NOS tubes and my Little Dot with Western Electric 403A tubes and a Burson V5i opamp...

I can't wait to let this thing run in for a couple of weeks, and then start with a few little mods, I have some Black Gate 330mfd@25V caps I'll use for the cathode bypass caps, I'll probably bypass them with a couple of .01mfd Auricaps I have if I don't use Sprague Vitamin Q .012@400V oil caps...I also have some Gudeman .51@300V Vitamin Q type oilers that I may try as coupling caps...

It's all fun and games...

P.S. I like how this site classifies me as a New Head Fi'er after joining over a decade ago! I lurk, I guess, and learn from others and only contribute if I have something salient to say. Glad this forum exists!

Ha.... you even beat me looking at your join date.... by one month! Congrats on your purchase.

Some interesting amps in your inventory by the looks of it, what model Little Dot have you? I have a MKVi+ and someone else here has the MKViii.

Good luck with your modding, don't forget take the advice here, and I think your bypass caps are a little too low, I think 0.1uF is best, but have fun!

Lucky to have got those Black Gate caps, some here have used the next best thing, Kaisei's.

 

[Rick_B]

Ha.... you even beat me looking at your join date.... by one month! Congrats on your purchase.

Some interesting amps in your inventory by the looks of it, what model Little Dot have you? I have a MKVi+ and someone else here has the MKViii.

Good luck with your modding, don't forget take the advice here, and I think your bypass caps are a little too low, I think 0.1uF is best, but have fun!

Lucky to have got those Black Gate caps, some here have used the next best thing, Kaisei's.

I bought a box full of those Black Gates several years ago, still have a bunch...
The Little Dot amp is the 1+....

 

[baronbeehive]

BTW, I had to comment on your profile pic... I always loved those TR4's, as a matter of fact I shall be seeing some today, I'm on my way to a classic car show later!

As a side note I had the same experience as you with mail from Hong Kong, got here quicker than local mail!