I am finally done with my Panasonic XR45 mod! After 6 months of playing with various mods, I don’t think there is anymore I can do.
There have been lots of information in various forums concerning XR45 mods and my mods are pretty much a collection of what I think made sense. Having the service manual is essential for anyone who wants to attempt any modification.
The mods were carried out in 3 stages:
Stage 1 – Replace all big caps in the power supply board with Nichicon caps. Replace the main filter cap with Jensen 4 pole cap. Replace main diode bridge with 4 IR HEXFRED. Replace the electrolytic caps feeding the output H-bridge transistors with Nichicon caps. Replace front 3 channel binding posts to WBT binding posts. Replace rear two channels to generic 5 way binding posts. Connect binding posts directly to the output coils via Audience Auric wires. Replace power supply wires between the two main boards with 14AWG DHLabs hookup wires. Replace AC main input with Furutech IEC socket.
This first stage mod made the panny sounded a lot more civilized than stock. The hint of digital glare was pretty much gone at this point. Details were good and soundstage was the most attractive quality, the speakers disappeared literally. Listening to music, it was on par with my Proceed AVP2 and AMP5 combo. And the panny did HT even better. So at this point, I decided to sell my AVP2 and AMP5 to upgrade my projector. The only problem that I had was the subwoofer out of the panny was not as good as the AVP2 in HT mode. The panny’s sub-out lacked details and bass was not tight.
Stage 2 – Replace coax digital in connector with Cardas RCA. Replace electrolytic decoupling caps on DSP board and main circuit board with blackgate standards. Replace subwoofer out coupling caps with blackgate NX.
I would say this mod made the most difference. The amp was very quiet to start with but with the mod the background got a lot blacker. It’s hard to describe until you hear it. All the details just came out from nowhere. Soundstage widened even further. The best word to use is the amp got more refined. However, I felt that the amp tended to run out of steam when playing loud in HT mode. So I decided to do stage 3 mod.
Stage 3 – The original big caps on power supply board and the output transistors are 1000uF. I changed them out with 2200uF Nichicon.
Only with 10 hours burn-in now, this mod does exactly what I wanted. The sound is so effortless no matter how loud it is. There is no sign of strain. Soundstage and imaging became more stable.
Approximate cost in parts and hours of labor is as follows: Stage 1 - $400+20-30 hours, Stage 2 - $100 + 5 hours, Stage 3 - $30 + 5 hours
The performance of this amp now completely beats my AVP2+AMP5 combo except in one area, subwoofer out for HT use. Even after changing out the coupling cap in stage 2, the sub-out still lacks behind the performance of AVP2 a level or two in this area, again in bass details and tightness, though much improved than before the mod.
Since the XR70 is supposedly very similar to XR45 in design, I hope someone can benefit from my experience when the XR70 becomes available. Digital amplification has finally made true high end audio and HT experience very affordable.
The rest of my systems as reference: Revel C30/F30/B15 (all with sonicap/mills resistors in crossover), SONY DVP-S9000ES w/modwright stage 3 and Empirical Audio transport mod. BPT 2.5U. VH audio Flavor 4 power cords to the panny and the transport. Virtual Dynamics Nite digital cable and Acoustic Zen Satori bi-wire speaker cable.
Mike
