Marantz PM66 KI tweeks - Page 47

Ben Hanke · 1st January 2012, 08:12 PM

Hmmm... OK, I'm going to cool my jets on that one then. The amp's sounding great as it is, so I'd do well to not risk breaking it again. The bridge was well worth it though.

Ben Hanke · 1st January 2012, 08:15 PM

btw the transistors seem identical quality. I bought them at the same time for the same price from Farnell and the packing label is the only indication that the manufacturer is different.

Ben Hanke · 7th February 2012, 05:41 PM

Hey guys, I forgot to say - just before I broke my amp, I was experimenting with PSU bypass caps without much luck. When I rebuilt it, I ended up drilling the PCB and adding 100uF/100v BG FKs across the main smoothers. I've been running with these for a few weeks now and I'm really happy with this combination. The overall character is the same, but it sounds more detailed. There's none of the harshness I got from trying other caps. I'm tempted to try tagging some Mundorf Supremes across too now.

nuryev · 19th October 2012, 04:47 PM

Hi Ben,
Where did you get your 56v 22000uF caps and the torroidal? I would like to try the mods in my PM66 KI.

Ben Hanke · 19th October 2012, 06:33 PM

Hey Nuryev,

My smoothing caps are 80v 10,000uF Black Gates, which are out of production and very rare. If I didn't have those then I think I'd buy some 80V 22,000uF Mundorf M-Lytic HC from Parts Connexion.

I got the second transformer by cannibalising a faulty KI amp that I bought on eBay.

Ben

nuryev · 29th October 2012, 03:22 PM

Hi Ben
Thanks for the reply. After looking around for ki tx and suitable caps I found 22000uf 63v Kendeil caps which appear highly rated. I have replaced most of the caps with Black Gates and was wondering would investing in the larger caps be worth the cost and effort without the transformer or until I source a KI transformer?

Would I have to change any other parts on the pcb if I go ahead with the cap upgrade?

Ben Hanke · 29th October 2012, 04:31 PM

No Roy, they'd just be a straight swap. Those Kendeil caps look nice - I'd say go for it.
I recommend getting some short lengths of good quality wire like Kimber 4TC. It's just the right gauge to fit through the existing PCB holes. I think the in-rush current should be OK at 22,000uF but you might want to pick up some spare fuses just in case.

nuryev · 14th November 2012, 11:57 AM

Hi Ben

The Kendeil caps have arrived as have the brackets and the Kimber cable :-).
After removing the original 50v Caps and cleaning the junk/glue off the board I accidently damaged a resistor (RN12). The part list describes the replacement as being 100K00 1% 0.4W resistor. I have a bag of spares from my cd mods and amp channel rebuild stock. The specific resistor i have on hand is Farnell (Element 14) Part no 337-419 Res 100K 1% 0.75w.

My question(s):
1) Is this part suitable to replace the original? And, if so..
2) Would I have to make any other component adjustments?

OR
the parts are really cheap..
3) Should I just place an order for some that is up to spec of the original resistor?

Thanks

Ben Hanke · 14th November 2012, 03:19 PM

I'm no expert, but I think it will be fine to use the one you've got. It's the same value with a higher rating. It's possible that the original is carbon and the replacement metal film, but I doubt it will make any audible difference.

davidwood15 · 3rd December 2012, 04:47 PM

Hi Guys, posted in another thread a while back but had no luck!

I had the problem of the power LED coming on and no clunk, so I opened up my amp, replaced both the 47R that are known to go and also a 1.2k that looked very charred.

Now my amp turns on, does the "clunk" but still refuses to have any output.

Does anyone have the slightest idea what may be causing this? This is my first ever project and it's stumped me!

1st January 2012, 08:12 PM	#461
Ben Hanke diyAudio Member Join Date: Dec 2007 Location: Vancouver, BC	Hmmm... OK, I'm going to cool my jets on that one then. The amp's sounding great as it is, so I'd do well to not risk breaking it again. The bridge was well worth it though. __________________ Modified Marantz CD63KI -> Modified PM66KI -> B&W 805S

1st January 2012, 08:15 PM	#462
Ben Hanke diyAudio Member Join Date: Dec 2007 Location: Vancouver, BC	btw the transistors seem identical quality. I bought them at the same time for the same price from Farnell and the packing label is the only indication that the manufacturer is different. __________________ Modified Marantz CD63KI -> Modified PM66KI -> B&W 805S

7th February 2012, 05:41 PM	#463
Ben Hanke diyAudio Member Join Date: Dec 2007 Location: Vancouver, BC	Hey guys, I forgot to say - just before I broke my amp, I was experimenting with PSU bypass caps without much luck. When I rebuilt it, I ended up drilling the PCB and adding 100uF/100v BG FKs across the main smoothers. I've been running with these for a few weeks now and I'm really happy with this combination. The overall character is the same, but it sounds more detailed. There's none of the harshness I got from trying other caps. I'm tempted to try tagging some Mundorf Supremes across too now. __________________ Modified Marantz CD63KI -> Modified PM66KI -> B&W 805S

19th October 2012, 04:47 PM	#464
nuryev diyAudio Member Join Date: Aug 2007	Your mods Hi Ben, Where did you get your 56v 22000uF caps and the torroidal? I would like to try the mods in my PM66 KI. __________________ NYV

19th October 2012, 06:33 PM	#465
Ben Hanke diyAudio Member Join Date: Dec 2007 Location: Vancouver, BC	Hey Nuryev, My smoothing caps are 80v 10,000uF Black Gates, which are out of production and very rare. If I didn't have those then I think I'd buy some 80V 22,000uF Mundorf M-Lytic HC from Parts Connexion. I got the second transformer by cannibalising a faulty KI amp that I bought on eBay. Ben __________________ Modified Marantz CD63KI -> Modified PM66KI -> B&W 805S


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29th October 2012, 03:22 PM	#466
nuryev diyAudio Member Join Date: Aug 2007	Hi Ben Thanks for the reply. After looking around for ki tx and suitable caps I found 22000uf 63v Kendeil caps which appear highly rated. I have replaced most of the caps with Black Gates and was wondering would investing in the larger caps be worth the cost and effort without the transformer or until I source a KI transformer? Would I have to change any other parts on the pcb if I go ahead with the cap upgrade? __________________ NYV

29th October 2012, 04:31 PM	#467
Ben Hanke diyAudio Member Join Date: Dec 2007 Location: Vancouver, BC	No Roy, they'd just be a straight swap. Those Kendeil caps look nice - I'd say go for it. I recommend getting some short lengths of good quality wire like Kimber 4TC. It's just the right gauge to fit through the existing PCB holes. I think the in-rush current should be OK at 22,000uF but you might want to pick up some spare fuses just in case. __________________ Modified Marantz CD63KI -> Modified PM66KI -> B&W 805S

14th November 2012, 11:57 AM	#468
nuryev diyAudio Member Join Date: Aug 2007	Hiccup Hi Ben The Kendeil caps have arrived as have the brackets and the Kimber cable :-). After removing the original 50v Caps and cleaning the junk/glue off the board I accidently damaged a resistor (RN12). The part list describes the replacement as being 100K00 1% 0.4W resistor. I have a bag of spares from my cd mods and amp channel rebuild stock. The specific resistor i have on hand is Farnell (Element 14) Part no 337-419 Res 100K 1% 0.75w. My question(s): 1) Is this part suitable to replace the original? And, if so.. 2) Would I have to make any other component adjustments? OR the parts are really cheap.. 3) Should I just place an order for some that is up to spec of the original resistor? Thanks __________________ NYV

14th November 2012, 03:19 PM	#469
Ben Hanke diyAudio Member Join Date: Dec 2007 Location: Vancouver, BC	I'm no expert, but I think it will be fine to use the one you've got. It's the same value with a higher rating. It's possible that the original is carbon and the replacement metal film, but I doubt it will make any audible difference. __________________ Modified Marantz CD63KI -> Modified PM66KI -> B&W 805S

3rd December 2012, 04:47 PM	#470
davidwood15 diyAudio Member Join Date: Sep 2012	Hi Guys, posted in another thread a while back but had no luck! I had the problem of the power LED coming on and no clunk, so I opened up my amp, replaced both the 47R that are known to go and also a 1.2k that looked very charred. Now my amp turns on, does the "clunk" but still refuses to have any output. Does anyone have the slightest idea what may be causing this? This is my first ever project and it's stumped me!

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