[hepatus1234]

Hi
I just got a bravo V2, which comes with a 12AU7 tube.
I don’t know much about tubes but I have read that 12AX7 are similar but with less gain.
Is this true?
Can I change the tube to a 12AX7 to reduce the amp gain and get lower output volume without damaging the amp or the phones?
Sorry about the ignorance but I don’t know much about electronic.
Regards

 

[CPL593H]

Quote:

Originally Posted by hepatus1234 /img/forum/go_quote.gif Hi I just got a bravo V2, which comes with a 12AU7 tube. I don’t know much about tubes but I have read that 12AX7 are similar but with less gain. Is this true? Can I change the tube to a 12AX7 to reduce the amp gain and get lower output volume without damaging the amp or the phones? Sorry about the ignorance but I don’t know much about electronic. Regards

Short answer: No you can't substitute a 12AX7 for the 12AU7. Here's a list of possible tube substitutions for the 12AU7 and some tube data:

TDSL Tube data [12AU7]

 

[gurusan]

Well my power button has broken

Has anyone found a decent replacement? Thanks

 

[leeperry]

a friend of mine is BLOWN away by this indeed version: New G2 Class A Hybrid Tube Headphone Pre Amplifier 6N11

I won't dare telling you what his previous amp was, but it was very solid stuff...and if it wasn't getting so hot, I'd be all over it

plus I'm afraid of tube rolling(bias adjusting seems to be a major PITA), if it becomes an OCD as much w/ opamps...no thanks

 

[ear8dmg]

Quote:

Originally Posted by gurusan /img/forum/go_quote.gif Well my power button has broken Has anyone found a decent replacement? Thanks

My power button is pretty much unusable. After much persistance I managed to get it to stay on and currently just unplug / replug the figure of 8 lead into the PSU. Not really a solution, but a workaround.

 

[gurusan]

I think I'll just put a toggle switch in there for now, but sort of wanted a decent pushbutton style swithc.

 

[hepatus1234]

Quote:

Originally Posted by CPL593H /img/forum/go_quote.gif Short answer: No you can't substitute a 12AX7 for the 12AU7. Here's a list of possible tube substitutions for the 12AU7 and some tube data: TDSL Tube data [12AU7]

Thanks
Glad I didnt try before ask
Regards

 

[ear8dmg]

So, I unexpectedly found myself ordering some HD600s when they dropped to £100 on play.com.

How does the Bravo handle them?

 

[jcoops16]

Quote:

Originally Posted by ear8dmg /img/forum/go_quote.gif So, I unexpectedly found myself ordering some HD600s when they dropped to £100 on play.com. How does the Bravo handle them?

When did play do that? All gone now I see.

Didn't drop the hd650's though did they? Im still waiting for them to drop below £200 like they did afew months back.

 

[ear8dmg]

Play had April 1st madness sale. It was one day only. There's a couple of threads in the full sized headphones forum. The HD650s weren't discounted. HD595s were £70 though.

 

[morphon]

Quote:

Originally Posted by ear8dmg /img/forum/go_quote.gif So, I unexpectedly found myself ordering some HD600s when they dropped to £100 on play.com. How does the Bravo handle them?

I borrowed a friend's HD600 when I got the Bravo V2. Suffice it to say that the combination worked very well. The Bravo has plenty of power to drive them. Off a line-level input I never got the volume control above the 10:00 position (which was playing classical music quite loud). Sound was very pleasant - good dynamics and detail. I didn't have another amp close by to do a comparison, but nothing seemed missing from the sound during the few days that I had the HD600 hooked up.

So, I can't tell you that it worked better than some other amp. But it sounded very good with power to spare.

 

[Amatsu]

Anyone heard any opinions about this one?
Miridiy Class A Hybrid Tube Headphone Stereo Amplifier - eBay (item 110514807480 end time Apr-05-10 02:07:20 PDT)

It appears to be another design based on the Indeed, it even says so in the description: Quote:

- Circuit design reference by Indeed Hi Fi Lab

 

[Judge Buff]

Quote:

Originally Posted by Amatsu /img/forum/go_quote.gif Anyone heard any opinions about this one? Miridiy Class A Hybrid Tube Headphone Stereo Amplifier - eBay (item 110514807480 end time Apr-05-10 02:07:20 PDT) It appears to be another design based on the Indeed, it even says so in the description:

If you can get it for cheaper than the Indeed or Bravo, do it! Then replace everything you can get off of the board with decent parts...

 

[lecky]

An update on my V1.2 Bravo (Second iteration of V1), with a Jan Sylvania 6DJ8 - I had put it aside finding that it wasn't making anything sound better than my Cyrus One, for instance the HD580s are fine from it up to a point, but really not as controlled and relatively natural sounding as from the Cyrus.

Then I got some Quart Phone 85, and the Cyrus makes them too bright, and the low end is really poor. However the Bravo is a fantastic match for these headphones - good control and balance, an uncanny soundstage (excuse the pun) - very low bass is of course limited, but for acoustic music it's fabulous, with a warm smooth mid and not too bright treble. Perhaps there's a smidge less detail, but nothing to complain about for what it offers.

So this amp has a new life. Perhaps I'll start modding it to see how far it'll go with these headphones.

 

[Judge Buff]

Quote:

Originally Posted by lecky /img/forum/go_quote.gif So this amp has a new life. Perhaps I'll start modding it to see how far it'll go with these headphones.

Lecky, you gotta replace the radial caps! At least replace the output caps with SilmicII or KZs. If your PS cap is 6800uF, you can go up to around 10K. Bass will improve and get cleaner (at least my Indeed did, as my PS cap was much smaller). My output caps are only 16V 470uF SilmicII and they are great sounding.

If you can find a decent Mullard E88CC or ECC88, you'll probably put the Sylvania up for good. I recommend an A-Frame Philips overall, though, for bang for the buck.