WestminsterLab Re-imagining Amplification

[Robifabs]

Hi guys,

Just a quick question: I am in the process of rethinking my rack and am reaching the physical limits of my current set-up. Can’t really push the walls any further.

Looking forward I might want to follow the pioneers of bridged REIs who are wonderfully cruising this thread (congrats and many thanks!!).

This would translate into a significant shelf space challenge unless I can place the 2 pairs on top of one another (without a proper shelf in-between).

I naturally suspect the recommendation is a side by side set-up (as portrayed in most set-up pictures I have seen so far if not all of them), but if I had to go for a vertical set-up:
- would I lose most of the gains of bridging 2 sets ?
- is there any strong technical counter-indication?
- or at the contrary, have the REI been designed to enable such set-up?
- etc…?

Thanks in advance for any contribution!

 

[MarkusBarkus]

...if I really *had* to stack them for some reason, I think I would build some sort of "mini-rack" I could place inside the main rack. That would give them a bit of isolation and room for airflow, and prevent any cosmetic scratches from stacking. With a little time searching, you could probably find a small rack/shelf/box that would work, even if you had to remove the back for cables.

 

[dbeau]

...if I really *had* to stack them for some reason, I think I would build some sort of "mini-rack" I could place inside the main rack. That would give them a bit of isolation and room for airflow, and prevent any cosmetic scratches from stacking. With a little time searching, you could probably find a small rack/shelf/box that would work, even if you had to remove the back for cables.

Good advice as I am considering REI and also wondered about what if a sencond pair thereafter in my limited rack space.
Another thought is placing the stock feet on other footers (EVP) to gain height for air flow.
I hope Westminster reps will jump in on this.

 

[MarkusBarkus]

...I have not tried it myself, but have considered EVPs on the Reis. I like the EVPs very much and use elsewhere. They would probably give a sufficient "heigh-gap" as well as prevent scratches with the felt versions. Even simpler than a shelf = good idea. Maybe adjacent to the stock feet?

 

[mxk116]

Good advice as I am considering REI and also wondered about what if a sencond pair thereafter in my limited rack space.
Another thought is placing the stock feet on other footers (EVP) to gain height for air flow.
I hope Westminster reps will jump in on this.

I currently use AV Roomservice EVPs under the existing footers of my WL Rei amps and Quest preamp. I do not stack the Rei amps (I do not use them in bridged mode but will add a second pair in the future). Along with RevOPods, I find the AV Roomservice products among the preferred products I use for component isolation.

The EVPs work well with the Rei amps but one must account for the fact that the front footer on the Rei amp supports (in my estimation, I have not measured this directly) ~ 60% of the weight of the amp. The massive transformer used in the Rei lies predominantly over the single front brass hemispheric footer. Therefore the 2 rear footers carry a fraction of that weight. EVPs are ordered based upon the weight they are required to support. Since the weight of the Rei is disproportionately distributed over the front footer, this must be accounted for when ordering. Otherwise the performance of the EVP will be compromised and one might risk crushing the front EVP if not matched properly to the mass it is supporting.

 

[MarkusBarkus]

...interesting point of information @mxk116

Those evps come in a weight *range* so I will revisit that aspect, with regards to weight distribution, before I set them up. Cheers.

 

[dbeau]

I currently use AV Roomservice EVPs under the existing footers of my WL Rei amps and Quest preamp. I do not stack the Rei amps (I do not use them in bridged mode but will add a second pair in the future). Along with RevOPods, I find the AV Roomservice products among the preferred products I use for component isolation.

The EVPs work well with the Rei amps but one must account for the fact that the front footer on the Rei amp supports (in my estimation, I have not measured this directly) ~ 60% of the weight of the amp. The massive transformer used in the Rei lies predominantly over the single front brass hemispheric footer. Therefore the 2 rear footers carry a fraction of that weight. EVPs are ordered based upon the weight they are required to support. Since the weight of the Rei is disproportionately distributed over the front footer, this must be accounted for when ordering. Otherwise the performance of the EVP will be compromised and one might risk crushing the front EVP if not matched properly to the mass it is supporting.View attachment 144807

True but maybe not too significant as each REI weighs in at only about 33#. Maybe a greater problem would be the placement on bottom REI over the air vents. IDK. I might get a couple of REIs/Quest in two weeks to trial and do have EVPs under current monos to try. Best

 

[gleeds]

Hi guys,

Just a quick question: I am in the process of rethinking my rack and am reaching the physical limits of my current set-up. Can’t really push the walls any further.

Looking forward I might want to follow the pioneers of bridged REIs who are wonderfully cruising this thread (congrats and many thanks!!).

This would translate into a significant shelf space challenge unless I can place the 2 pairs on top of one another (without a proper shelf in-between).

I naturally suspect the recommendation is a side by side set-up (as portrayed in most set-up pictures I have seen so far if not all of them), but if I had to go for a vertical set-up:
- would I lose most of the gains of bridging 2 sets ?
- is there any strong technical counter-indication?
- or at the contrary, have the REI been designed to enable such set-up?
- etc…?

Thanks in advance for any contribution!

Robifabs,
Sorry for the slow reply. Just back from a family holiday. At 4X, the power heat generation is increased considerably over a single pair. Allow me to speak with Angus this evening, and I'll reply as soon as I have the answer. I have considered such an arrangement but have no experience yet trying this configuration for more than a brief demo. Back to you soon.

 

[gleeds]

Robifabs,
Sorry for the slow reply. Just back from a family holiday. At 4X, the power heat generation is increased considerably over a single pair. Allow me to speak with Angus this evening, and I'll reply as soon as I have the answer. I have considered such an arrangement but have no experience yet trying this configuration for more than a brief demo. Back to you soon.

Thanks to Markus Barkus and MX116 for their suggestions. What I'm after from Angus is the recommneded air space between the amplifiers. Once known, a simple correctly size shelf as suggested should do the trick.

 

[MarkusBarkus]

...by the way @gleeds the VR50s sounded fab powered by four Reis and the Quest at New Life Audio Friday. I brought along a couple more old-time audio pals for the demo, and they thought the sound was terrific. Very natural. Whoah... very deep sound-stage. The Westy set-up is sooo clean. Lumin and Rockna front-end were also very nice. I did not miss my Olympus at all for the demo. Thanks for helping Shawn get sorted out with the second set of Reis and cables. Primo set-up.

 

[Robifabs]

Thanks to all for you answers and ideas.

@gleeds, looking forward to when you hear back from Angus.

@dbeau and @MarkusBarkus, I didn't know about EVPs, went to check online and will be in touch with them to discuss optimal solution in their view (taking front/rear weight repartition into consideration). Thanks for the tip! I will share if anything interesting comes out.

@mxk116 , hopefully you will find the time to share and debrief when you receive all these electronics. Thanks in advance!

On my end, I currently have 2 Thrax Heros monoblocs in my rack and heat generation-wise, they are world champs compared to the REIs. I could use them to cook my breakfast eggs & bacon as with any good old pure A-class amps. I use an automated system of very silent fans to ensure temperatures remain bellow 95F at all time (my rack is installed in a cabinet that I can close and open on both front and back sides). Variable speed depending upon measured temperature make them hardly impossible to hear even when not playing music and listening at very close range. I am not worried about heat dissipation but maybe I should be!

 

[gleeds]

Thanks to all for you answers and ideas.

@gleeds, looking forward to when you hear back from Angus.

@dbeau and @MarkusBarkus, I didn't know about EVPs, went to check online and will be in touch with them to discuss optimal solution in their view (taking front/rear weight repartition into consideration). Thanks for the tip! I will share if anything interesting comes out.

@mxk116 , hopefully you will find the time to share and debrief when you receive all these electronics. Thanks in advance!

On my end, I currently have 2 Thrax Heros monoblocs in my rack and heat generation-wise, they are world champs compared to the REIs. I could use them to cook my breakfast eggs & bacon as with any good old pure A-class amps. I use an automated system of very silent fans to ensure temperatures remain bellow 95F at all time (my rack is installed in a cabinet that I can close and open on both front and back sides). Variable speed depending upon measured temperature make them hardly impossible to hear even when not playing music and listening at very close range. I am not worried about heat dissipation but maybe I should be!

Robifabs, as suspected, Angus does not recommend stacking the amplifiers. That said, a simple shelf elevating the bridge Rei from the primary one, allowing a 3-4 inch gap between the top of the base level amplifier, would be sufficient. You should allow some space for the top amplifier as well. I'm unsure if you can. The open-air option you described and the fan system should work well, especially compared to your current amplifiers. If you're in the US, we can arrange for you to test them beforehand. However, based on the experience you are reporting, you should be good.

 

[Robifabs]

Robifabs, as suspected, Angus does not recommend stacking the amplifiers. That said, a simple shelf elevating the bridge Rei from the primary one, allowing a 3-4 inch gap between the top of the base level amplifier, would be sufficient. You should allow some space for the top amplifier as well. I'm unsure if you can. The open-air option you described and the fan system should work well, especially compared to your current amplifiers. If you're in the US, we can arrange for you to test them beforehand. However, based on the experience you are reporting, you should be good.

Thanks a lot Gary! That helps a lot indeed.
The challenge I would have then, would be to add a thin enough shelf in my existing rack, to make the staking work within the available hight of my shelf. Does anyone have an experience with carbon fiber or any thin materials, robust and non resonating enough that I could potentially use to create that additional shelf? It would be resting on the main shelf and benefit from the decoupling of the main stack structure. No perfect but good enough if I don't create new vibrations with the additional shelf I guess... Just thinking up-loud guys. Thanks in advance for any contribution

 

[Arif_in_Japan]

Thanks a lot Gary! That helps a lot indeed.
The challenge I would have then, would be to add a thin enough shelf in my existing rack, to make the staking work within the available hight of my shelf. Does anyone have an experience with carbon fiber or any thin materials, robust and non resonating enough that I could potentially use to create that additional shelf? It would be resting on the main shelf and benefit from the decoupling of the main stack structure. No perfect but good enough if I don't create new vibrations with the additional shelf I guess... Just thinking up-loud guys. Thanks in advance for any contribution

I use these https://www.finite-elemente.eu/en/carbofibre/ with Harmonix million as isolators. I am wondering if they can do a size for you since they do it for their higher lines.

 

[Robifabs]

Another Quick one: what is the cable between 2 bridged REI? Standard XLR or specific? Thanks!

 

[Robifabs]

I use these https://www.finite-elemente.eu/en/carbofibre/ with Harmonix million as isolators. I am wondering if they can do a size for you since they do it for their higher lines.

Thanks. I’ll have a look

 

[Vinylshadow]

Hi guys,

Just a quick question: I am in the process of rethinking my rack and am reaching the physical limits of my current set-up. Can’t really push the walls any further.

Looking forward I might want to follow the pioneers of bridged REIs who are wonderfully cruising this thread (congrats and many thanks!!).

This would translate into a significant shelf space challenge unless I can place the 2 pairs on top of one another (without a proper shelf in-between).

I naturally suspect the recommendation is a side by side set-up (as portrayed in most set-up pictures I have seen so far if not all of them), but if I had to go for a vertical set-up:
- would I lose most of the gains of bridging 2 sets ?
- is there any strong technical counter-indication?
- or at the contrary, have the REI been designed to enable such set-up?
- etc…?

Thanks in advance for any contribution!

Could you use Live Vibe Audio's brass decoupler sets and jr. racks?

 

[mxk116]

...interesting point of information @mxk116

Those evps come in a weight *range* so I will revisit that aspect, with regards to weight distribution, before I set them up. Cheers.

I've attached some images to illustrate how I applied the AV RoomService EVP's to the each Rei chassis in my system. YMMV

One (1) 2" x 4" HD EVP for the front footer, two (2) 2" x 2" HD EVP for the rear footers. I used square EVP's because the round shape was not available at the time. Either shape will work as long as it is sized correctly for the weight it needs to support.

In this case, the 2" x 4" HD EVP has a load range of 12 - 76 lbs. (5.4 - 34.4 kg). I assumed the load on the front footer was 60% of the weight of the chassis (0.6 x 35.2 lbs) which equals 21.12 lbs.

I did similar calculation for the rear footers (0.4 x 35.2 lbs ÷ 2) which equals ~7 lbs per rear footer. This matches the load range of the 2" x 2" HD EVP.

One can see in the images attached that the load needs to be centered on the EVP as best one can be or the footer will distort the EVP and compromise its performance.

I hope this helps visualize the forces at play. As I stated in a previously in this thread, AV RoomService and Ayra Audio Labs (RevOpods) have become my first choice solutions for equipment isolation and vibration control.

 

[Robifabs]

I've attached some images to illustrate how I applied the AV RoomService EVP's to the each Rei chassis in my system. YMMV

One (1) 2" x 4" HD EVP for the front footer, two (2) 2" x 2" HD EVP for the rear footers. I used square EVP's because the round shape was not available at the time. Either shape will work as long as it is sized correctly for the weight it needs to support.

In this case, the 2" x 4" HD EVP has a load range of 12 - 76 lbs. (5.4 - 34.4 kg). I assumed the load on the front footer was 60% of the weight of the chassis (0.6 x 35.2 lbs) which equals 21.12 lbs.

I did similar calculation for the rear footers (0.4 x 35.2 lbs ÷ 2) which equals ~7 lbs per rear footer. This matches the load range of the 2" x 2" HD EVP.

One can see in the images attached that the load needs to be centered on the EVP as best one can be or the footer will distort the EVP and compromise its performance.

I hope this helps visualize the forces at play. As I stated in a previously in this thread, AV RoomService and Ayra Audio Labs (RevOpods) have become my first choice solutions for equipment isolation and vibration control.

View attachment 145028View attachment 145029View attachment 145030

Thanks a lot! Brilliantly clear, well thought of and very helpful. The hight of the front & rear EVPs are the same, correct?

 

[gleeds]

Another Quick one: what is the cable between 2 bridged REI? Standard XLR or specific? Thanks!

Robifabs,

Cable lengths depend on how you configure your bridged pairs. Two methods.

Method one: Use two pairs of discrete XLR cables driven directly from your pre-amplifier outputs. Cable set one is standard phase and cable set two inverted phase. This constitutes one channel. Left or right of a bridged pair, four interconnects make up both channels. In that case, the interconnect length is whatever you choose from pre-amplifier to amplifier.

The next thing needed is the "ground bridge wires" connecting the grounds of each left and right channel pair of amplifiers. Generally, we offer them in 20'' lengths unless for some reason, you do not place the amplifiers side by side which is usual and customary. Longer lengths can, of course, be provided.

In bridged mode, your speaker cables' hot and ground legs are connected to the + binding post of each amplifier pair. No special speaker cable modification is needed.

Method Two:
When using only one set of standard phase interconnects (left and right), connect each channel's left and right cables to the lead amplifier. We then supply two, one each for left and right bridged channels inverted phase interconnects to accomplish the bridging between the amplifiers (also approx. 20" in length).

We can also discuss why and how we decide between these options. For now, suffice it to say that both work splendidly and accomplish the goal of perfectly bridging each channel without fuss or complication.

I am running to an out-of-office meeting but will post a schematic of both methods later today, illuminating how Westminster elegantly accomplishes the goal.

On shelving for your application, carbon fiber is always a suitable material, although it is a bit overkill. Either 1/2" MDF or fabricated sheet plexiglass will work perfectly, providing a stable platform for the top set of amplifiers and the needed clearance. Since we have a machine shop stateside, we can fabricate this for you, and you can purchase a set of bridged amplifiers at no cost.
Note: The Reis is not highly susceptible to air and floor-borne vibration, especially when not placed near your speakers. MX116 has his Reis placed between his powerful Magico S5s; therefore, I suspect the extra steps taken with isolation to be beneficial.

Fun fact: Angus originally designed the Reis for bridged operation. Unlike many amplifiers available for stereo and monoblock operation, the Reis was optimised from day one to be electrically perfect when using a single or a bridged pair of monoblocks.