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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
baaach
22 posts
 

This capacitors shootout with sound clips is worth checking out.  
See if the differences are noticeable to you, and see what your preferences are. 
For me, it’s not a piece of music I’m familiar with or a piece that I’d choose for this type of test.  Also, the way these caps affect a DAC may or may not be relevant to how same brand-model of caps with different values would result in an amp.  
But it’s worth noting how subtle the differences are, not night and day for sure, given the disparity in price and exotic-ness of the materials and construction process.  

https://sw1xad.co.uk/capacitor-shootout/

baaach
22 posts
 

@tablejockey 

I like the tidy form factor of a well built integrated amp.  No extra cables to consider.  And no extra shelf space needed.  If I go separates, then I’d go all the way with a pre and dual monoblocks, which would multiply number of cables and tubes quickly.  Unnecessary for how loud I want to play in my room with my speakers and music of choice.  A well sorted integrate amp with the right caps and tubes is all that’s necessary.  

bryoncunningham OP
907 posts
 

Hi Tablejockey,

Yes, I have considered adding a preamp. I know some folks have much better results with a preamp compared to running a source directly to their amp. In this particular system, it's unclear to me what benefit a preamp might add. Here's my reasoning: This system only has one source, so no need for source switching. The output impedance of the Benchmark DAC3L out is 30 ohms (for the RCA output), and the input impedance for the PL amp is 100k Ohms, so a very good ratio of 3333:1. The Benchmark DAC3L has a volume control. I keep the volume at the 3 o'clock position for most listening, which is at or near unity gain. The short distance between the dac and the amp allows me to use .5m unshielded interconnects, which I tend to prefer over most shielded interconnects.

That all said, I'm happy to be wrong about the benefits of a preamp in this setup. Let me know if you think I'm missing something.

Bryon

 

baaach
22 posts
 

@bryoncunningham 

you don’t need a preamp then, unless you want some coloration between the DAC and the amp.  

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