2. amps-preamps
  3. 193642-3931

Help me mod my tube amp

Hi all,

I'm interested in modifying my Prima Luna Dialogue 4 amp. The amp is about 15 years old and still sounds pretty good. But in the past I've had fun modding preamps and speakers and seeing what can be improved, so I'd like to try improving the SQ of this amp. I haven't modded an amp before, so I open to suggestions about capacitor upgrades or anything else. You can see a picture of the internals of the amp here. This amp resides in a secondary system, which is:

Mac mini --> Benchmark Dac3 --> Prima Luna Dialogue 4 amp --> Dali Phantom S-180 speakers + Rhythmik F12G-SE-PEQ subwoofer (via high level speaker input)

Power: dedicated line --> Maestro outlet --> Shunyata Hydra 8 power conditioner. Cables are Shunyata and DH Labs.

Current tube configuration in Prima Luna amp: GE Military stock 12AU7, Gold Lion 12X7, Tung Sol KT120

These days, I tend to like things on the slightly warm side of neutral. I appreciate increased resolution, but not at the expense of organic tonality and musicality. Any help would be greatly appreciated!

Bryon

 

bryoncunningham
bryoncunningham OP
901 posts
 

Thanks SNS. I read above that you upgraded the resistors in your PL amp. I bought this amp new around 2012. Can you tell from looking at the picture I attached whether the resistors are Takman or something else?

Bryon

sns
3,921 posts
 

PL went to Takman around 2008, yes, those are Takman, you're good to go. I don't think I mentioned this prior, but I also upgraded film cap bypass caps on the big power supply caps, can't recall which caps I used.

bryoncunningham OP
901 posts
 

Thanks, SNS. For the bypass cap, I think you're talking about the yellow cap marked "Swellong MPT 630V" in my photo. Is that right?

tablejockey
4,065 posts
 

I'm sure your amp is performing better than it already  is.

How my much in parts/ labor are you in?

"For the 12AU7s, I added NOS Brimar from Upscale Audio."

I looked up the current price to compare what I paid 8 years ago- ouch, but not obscene. Still in my PL.

My 11 year old PL HP will get the makeover as a DIY project eventually. For now, it's a reliable daily driver like my 67 Macintosh tube tuner.

 

 

 

 

sns
3,921 posts
 

Yep, the yellow one is correct.

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