Tubes and capacitors upgrade?

[chuotcon15]

I have an original Crack + Speedball pairs with Sennheiser HD650. I now want to upgrade the new both tubes and capacitors to get the maximum power. As a amatuer in DIY headphone amp, I really don't know well about tubes and capacitors upgrading. Could you guys please help me to find the best tubes around $70 - $100? I also want to upgrade capacitors. Please give me some specific sites to buy them. Thank you.

[Nathan]

If your goal is to increase power, and by that I presume you mean maximum spl, changing tubes or caps isn't going to do it. I can't imagine you are finding the Crack with Speedball not sufficiently powerful to drive the 650's to ear splitting levels.

[chuotcon15]

No, I mean to get the max potential sound. Thanks for your reply.

[Grainger49]

Now that we understand... there is a whole thread on Tube Rolling In Crack.  It covers a number of equivalents and listening experiences.

There are numerous threads already on capacitor upgrades.  Many have swapped film caps in where the output 100uF electrolytics are.  Others have put film caps or film bypass caps into the power supply.  There are only 5 capacitors in the amp to upgrade and you don't need to upgrade all of them.

[Nathan]

I am quite happy with my current tube compliment, a Tung Sol 5998 and a Mullard CV4003 but those are above your price range.

What can I can recommend is an RCA clear top 12au7 and an RCA 6as7g. I doubt you'll spend $40 for the two. eBay can be a source.

Next, you may want to look for Russian bypass caps for the 100uf . Again, eBay is your friend and I doubt you'll spend $15 for the pair

[chuotcon15]

@Nathan. I could afford the Tung Sol 5998 and a Mullard CV4003, but I saw the NOS/NIB, Jan, and Chatham 5998s. What are those? which one is best? which one should I get?
And the "Russian bypass caps for the 100uf", can you please give me specific code name Or it would be nice if you you me a link? I am not clear about this. And if I have those caps, where do I solder on (terminal #?)? Thanks for your help.

[Grainger49]

These are 0.1uF at 600V:

http://www.ebay.com/itm/2x-0-1-uF-600V-teflon-HI-END-capacitors-FT-3-NEW-/201273268011?pt=LH_DefaultDomain_0&hash=item2edcd2572b

I have bought from this seller for over 10 years.  Always satisfied.

[chuotcon15]

@Grainger 49, may I ask you a stupid question (I thought)?
How many those Caps should I buy? And where do I solder? Thanks a lot!

[Grainger49]

You would need 2 (the auction is for 1).  One goes from 6U to 7U the other from 9U to 10U.

[Deluk]

Auction is for two 2x 0.1 uF 600V teflon HI-END capacitors FT-3 NEW
Also says "Lot of 2 capacitors". 

[Paul Birkeland]

I will point you to the two pertinent threads:

Output Capacitors in the Crack
Tube Rolling with Crack