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Primaluna Prologue Four mods/upgrades

I've had a new Prologue Four for a few months now. The midrange was a bit shouty/ screechy. I've replaced the 2 small 'Realcap' caps in the input section for same value 'Mundorf Evo Oil'. This added clarity to all frequencies. I have now replaced the input resistors to TAKMAN carbons. This has really cleaned up the screechy midrange. I will eventually replace the other 4 'realcaps' on the autobias board.

Just wondering if anyone else has any advice or experience with similar simple mods to primaluna. I also have the Prologue Premium Pre. These are great amps for the money.
 
I don't think that changing the caps or resistors in a feedback loop will effect the sound much at all. The feedback loop does the correction, not the better parts.

You are also devaluing the amp for later sale by tampering. "Improved by amateur" is not very easy to sell.

Yes you are right... not easy to sell maybe... but changes in parts are usually hearble without any efforts - this is only my personal opinion of course. Primaluna Four is non feedback design... quote from their website: "The ProLogue Four starts with the same basic topology as the top-rated ProLogue One integrated amplifier. But further improvements are realized from new driver and phase splitter circuitry. The result is no need for any negative feedback. This means even more natural tonality and better overall musicality."

And in case of resistors... if you'll take a look at new Primaluna range, what they did to improve sound of it, you can see TAKMAN Carbons on Anodes of preamp tubes... so it is certainly hearable change too.

For example here (Takmans are the pink ones): DiaLogue Premium Integrated — PrimaLuna USA
 
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academia50

Member
2013-01-16 2:52 pm
TAKMAN RESISTORS
If you bought a lesser amplifier, you would pay hundreds to make this upgrade. Easy to identify through their pink color, these premium resistors from Japan are popular with those who rebuild and upgrade their gear. "Modders" love TAKMAN for their low noise, linearity, and musicality.

:rolleyes::witch:
 
I have swapped out resistors in several amps. I used an expensive pair of Audio Note input resistors in place of the OE ones in an Alchemist Forseti amp. The difference was huge, far more clarity and detail. I also swapped the OE input resistors in my haedphone amp with Kiwame and again a massive change to a very warm, smooth, rich sound from the Kiwames. Just about to swap out the cheap input resistors in my PrimaLuna Prologue four. Going with Takman as PrimaLuna use them in their better gear. I'm hoping for a more refined sound.
So, in my experience, input resistors make a very big difference, they are after all at the beginning of the chain.
Hope this is helpful.
 
I left the PL four power amp unused and switched to the PL Prologue Premium Pre with my fully re capped Alchemist SS power amp. Initially although it was a nice sound, I bought a pair of Baldwin Long plate halo getter 12AU7A and put them in the middle. WOW! immediately it was a different system. The horrid mid glare and slow bass vanished and I had a far more 3D, tight but rich fast sound and a bit more treble air. A bit more dynamic also. I'm going to get shot of the inner pair of PL 12AU7 also. Fancy trying some RCA clear tops. Anyone else had good experiences with NOS tubes in PL?
 
Hi,

I have recapped my Prologue One (same as Prologue 4 but integrated amp). As already mentioned the two 0.1uF/600V Film Caps in the front make a difference. I have put the Mundorf Supreme Silver Oil, and also changed the electrolytic 22uF/450V nearby. Immediate improvement in tonality, crispness and precision.

On the Autobias Board I replaced the existing film caps with Mundorf EVO Silver Gold, they fit nicely on the board due to the sleek dimensions. It is advisable to change them too as those are in the signal-path as coupling caps on the Grid 1 of the output tubes. Improved soundstage depth and dynamics overall, but the Evos need several days or weeks to really settle-in : they add some edginess to the treble, but gradually ameliorating.

Expect also a really big improvement in the low-end and soundstage by replacing the 100uF/450V Electrolytic cap in the Power Supply, I did also replace the 100uF/100V and 100uF/160V on the input transformer. Just install some top quality, low ESR ones there. Well my Prologue One is running since 2007 and has operated up to 38000 hrs, so changing the electrolytics is anyway a good (and necessary) action.

This all really cleans up the sound and opens up the whole frequency range.
Other tweaks I did already years ago: soldering the grid to anode connection on the output transformer taps (pseudo triode mode), using KT66 and KT77 tubes of Gold Lion brand.

Much fun with that amp !
Mario
 
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I have the prima luna prologue premium integrated amplifier. I read somewhere that the audyn copper caps were top of the line - does anyone have experience with them? also does anyone have a schematic for this amp? I don't care about the autobias board, only the parts in the signal path.

As for tubes, i swapped out the default tubes with Psvane Mark II 12au7 and 6sn7. These are premium tubes and the sound it fantastic with them.
 
Some great info. of experiences with PL gear. Really helpful, Mario, as my power amp could do with some bass. I will try the electrolytics in the transformer upgrade that you suggest.

Every change I've made has taken it more in the direction I'm after. I've discovered that the stock 12AX7 and 12AU7 have a nasty mid range colouration/ distortion and once run in they loose all the airy high end also. I've gone GE JAN 5751 and Baldwin 12AU7A. This was a huge improvement..., clear, detailed, smoother, richer sound.

In my pre amp, I've used Sylvania 5963 and Baldwin 12AU7A. The Baldwin are incredibly sweet, rich, lush sounding. The Sylvania is similar but has more high frequency extension.

Back to the power amp, I am still using the PL EL34's. I am considering trying new Mullards or Tung Sol.
 
I've had a new Prologue Four for a few months now. The midrange was a bit shouty/ screechy. I've replaced the 2 small 'Realcap' caps in the input section for same value 'Mundorf Evo Oil'. This added clarity to all frequencies. I have now replaced the input resistors to TAKMAN carbons. This has really cleaned up the screechy midrange. I will eventually replace the other 4 'realcaps' on the autobias board.

Just wondering if anyone else has any advice or experience with similar simple mods to primaluna. I also have the Prologue Premium Pre. These are great amps for the money.

Was Looking at Prima Luna - But made in China