Ben, GV -- I need your assistance...

Early B.

I recently purchased a pair of Rogue Audio M-120 monoblocks and I'm considering doing some minor modifications to them. At a minimum, I'd like to change out the two pair of Wima caps (1.5 uF & 0.1 uF) and replace them with Sonicaps. Is it worth it? Do you guys see any other mods that can be made?

Ben -- if I buy the parts, can you help me with the install?

Thanks.


P.S. -- this particular model runs very hot. Is there a way to cool the amps down a few degrees?

ben62670

Well if you want to mod it I don't mind helping out. As for the Wilma's they have a very good rep. There are few other caps that I would consider changing. I am not sure what the resistors are either, but changing a few resistors in the signal path might be beneficial. Lots of tube gear used carbon resistors, but the metal films have come a long way. I am sure GV would know much more on this than me. I am comfortable with doing the upgrades, but component selection is something I would rather get some help on.
Ben
Ben

Early B.

ben62670 wrote: »

Well if you want to mod it I don't mind helping out. As for the Wilma's they have a very good rep. There are few other caps that I would consider changing. I am not sure what the resistors are either, but changing a few resistors in the signal path might be beneficial. Lots of tube gear used carbon resistors, but the metal films have come a long way. I am sure GV would know much more on this than me. I am comfortable with doing the upgrades, but component selection is something I would rather get some help on.
Ben
Ben

Thans, Ben. We can discuss compensation and favorite beer later on...

I'm really interested in taking these amps to another level since I plan to hold onto these for a long time.;)

ben62670

Early B. wrote: »

Thans, Ben. We can discuss compensation and favorite beer later on...

I'm really interested in taking these amps to another level since I plan to hold onto these for a long time.;)

Your presence and some take out is payment enough:) My favorite beer is Arizona Iced tea. Not much of a drinker here.
Ben

Systems

Hi Brad,without seeing a schematic it would be hard to make any recommendations because you can't determine what parts are in the signal path etc.Parts quality looks pretty good,the writing on the Wima's indicate they are their MKP-4 series. These are good polypropylenes so even if they are in the signal path I really don't know if swapping them for SonicCaps is going to improve things. Maybe maybe not.

All the .25 watt resistors appear to be metal films,the big dropping resistors are metal oxides.Replacing some of metal films with Caddock's http://www.caddock.com/ in key places(input,feedback) would be a possibility,but again a schematic would be necessary to determine which ones.

treitz3

Yeah, I don't know if the swap from Wima to Sonicaps will yield that much of a change either. Just a reminder, Klaus uses Wima caps in the Odyssey gear if that tells you anything.

Early B.

treitz3 wrote: »

Yeah, I don't know if the swap from Wima to Sonicaps will yield that much of a change either. Just a reminder, Klaus uses Wima caps in the Odyssey gear if that tells you anything.

If those Wima caps are in the signal path, I wanna change 'em. Klaus' most advanced tricked out Odyssey (I forgot what he called it) used Sonicaps.

The Rogue M-120 monoblocks were also factory modded into a "Magnum" model. Here's what they did:

- Larger higher performance output transformers
- Larger power supply
- Power supply mods
- Ultra high quality interstage coupling capacitors
- Precision Dale-Vishay resistors
- Upgraded binding posts
- Gold tube sockets
- Upgraded input and output tubes
- Harmonic Technology silver wiring

I only want to perform the mods that will provide the most sonic benefit at a reasonable cost (under $200 for parts). I'm not sure if upgraded binding posts and gold tube sockets will make as much of a sonic difference as changing out the coupling caps.

Systems

Its a pretty safe bet that atleast the 1.5uf Wima's are in the signal path.I see they used atleast 4 of the Dale resistors in that amp but the Caddocks are better.http://www.caddock.com/Online_catalog/Mrktg_Lit/TypeMK.pdf

fredv

Brad, I recommend to listen to the blocks for a little longer before doing any mods. This way, you can get familiar to the sound and will be able to experience the change when new caps are in place.

It is hard to say for sure without the schematic. Looks like the 1.5uF Wima's are the coupling caps from the phase splitter into the output tube. The value seems to be a little high. A lower value should give a faster response in general.

Early B.

Update --

I got a schematic from Rogue. Unfortunately, it doesn't include the values on it. Nevertheless, since both pair of Wima caps are in the signal path, I'll start with changing them out. Gonna try some Mundorf Supreme caps...

ben62670

This will be fun. I eagerly await your impressions. I feel it may take a while to burn in those big caps;)
Ben

Systems

Early B. wrote: »

Update --

Nevertheless, since both pair of Wima caps are in the signal path, I'll start with changing them out. Gonna try some Mundorf Supreme caps...

Thats a good starting point.