Inherited monoblocks - What model is this and how to improve?

[Paul Joppa]

Fortunately, Natural Sound forwarded to me the old instructions for the Magnequest iron upgrade package for the Paramour II. That package is no longer available, but the instructions are mostly the same. I'll see if I can edit them or at least provide a side commentary to adapt them to the currently-available upgrade. I think it can all work out without drilling holes or changing the appearance. It may take me a while, I have a lot of things on my plate at the moment - but if the OP decides to go ahead with that upgrade, I'll raise the priority.

I agree with PB, keep the 12AT7. Sometimes I get carried away with possibilities and lose track of what's practical  :^)

[absolutk]

Sincere gratitude for all the knowledge.

Given the sheer number of open projects, I think it is prudent to shelve the iron upgrade for now, and the tube change permanently. Though, I will get replacement 12AT7s, redo the casework and upgrade the 0.1uF per Natural Sound's advice. Is that value critical? I found a pair of JantZen 0.15uF 2% caps (Red) in my parts bin. Would those work?

[Paul Birkeland]

0.15uF would work just fine in those.

[absolutk]

Excellent - thank you!

0.15uF would work just fine in those.

[Paul Birkeland]

The improvement from the iron upgrade would be monstrous.  It goes well beyond the subjective terms.  You will get more power out of the amps and significantly deeper/cleaner bass.

[RPMac]

The improvement from the iron upgrade would be monstrous.  It goes well beyond the subjective terms.  You will get more power out of the amps and significantly deeper/cleaner bass.

+1 for the iron upgrade. My Stereomour compares well with my amps with Magnequest iron.
With the iron upgrade, would he have the option of converting to 45 output tube op points?

[absolutk]

I'll clarify - I would *love* to pursue the iron upgrade. It's just that I'm stuck in a rut amongst two audio projects (this and a small solid state integrated); I need a simple win to get unjammed. On both, it's the chassis.

Is there a universal method used to secure the Paramour plate to a chassis? Internet pictures don't seem to indicate so. Right now they sit atop two rough rectangular frames, unsecured. I suppose I'd have to measure/drill holes and screw them into the chassis I design?

Also, would it be a major faux pas to move the I/Os to the rear instead of the top? Is having them on the top a Bottlehead signature?

[Paul Birkeland]

The iron upgrade does indeed open up the #45 more so than the stock iron.

No, it's not a faux pas to mess with the enclosure design.  We use the plate and base method because it's incredibly easy to go back in and fix issues or apply modifications down the road compared to having components mounted to multiple panels at different angles.  Here is an example of a pair of Paramour monoblocks that I converted into a stereo amp.

You can get binding posts intended for speakers and just install them through the wood base.  I sell a metal plate and IEC power entry module on eBay that can be installed into wood with a hole saw and some wood screws.  To move the RCA jacks to the wood base, I install the RCA jack on the biggest fender washer I can find, prewire the RCA jack, drill a hole in the base, then use polyurethane adhesive to glue the fender washer to the wood.  If you have an oil finish on the base, you'd need to sand it off first.

[Natural Sound]

Is there a universal method used to secure the Paramour plate to a chassis? Internet pictures don't seem to indicate so. Right now they sit atop two rough rectangular frames, unsecured. I suppose I'd have to measure/drill holes and screw them into the chassis I design?

Most people are fine with using gravity to hold the top plate in place. But I understand that there are some instances where this is insufficient. What I've seen most commonly here is to glue some wood blocks in the corners of the wood base and then drill some holes in the top plate. Then it's just a matter of screwing the top plate down into the newly installed blocks.

Alternatively you can purchase some bamboo bases from Blumenstein Audio. Their design captures the top plate in a groove around the top of the base.
https://www.blumensteinaudio.com/all-products/wooden-amplifier-bases-for-bottlehead-amplifiers