Antelion Evo class A bias settings and listening

[Urbinator]

Hi guys after some guidance as I am using a non gryphon pre amp and therefore no green bias. Choosing bias setting and time for it to settle in seems a little vague. The manual describes bias L as more for standby to get the amp to working temperature and then you can choose either Bias M for up to 50w of pure class A playback or H for pure class A.
How long should you leave the amp for before listening when first switched on? When switching from L to M or H, how long should the amp take to settle in to that bias setting? From my experience I usually turn the amp on in bias L and wait 45 minutes. If choosing M or H I find it seems to settle in within about 7 minutes.
Bias L is something else I am unsure of, the amp also drives my AV system left and right channels when not listening to music. It seems okay for most movies in L mode or even for just background music, is that okay and if so, what is the output setting wattage before it hits class A/B
Final and to me a weird one, the amp gets warm in H as expected, but not really hot when listening to music around 72db, it starts to get really warm though at higher levels such as 88db, when you rally start to drive the speakers. That seems weird to me though as I though it was suppose to be opposite to that for a class A amp, running cooler at higher volumes.

Speakers being driven are the TAD CE1's which are quite difficult to drive.

All a learning curve, so would appreciate feedback, both good and bad.

Regards, Lee.

 

[aangen]

Your findings match mine. 45 minutes seems a good amount of time to warm up. Switching from one setting to another doesn't seem like a lot of time is needed for it to adjust. The point of the LMH settings is for you to adjust the point where the amp switches from Class A to Class AB. Movies in Class AB are fine. Music when you aren't paying close attention, Class AB may be fine as well. You get all the power the amp can make in any setting. It is just the point where it switches from A to AB that changes. In High Bias mode it is Class A only. If you are listening intently and want the best sound the amp can offer, High Bias is the way to go. Anything less, no big deal. The efficiency of your speakers makes a difference. I used to listen in M mode a lot until a friend convinced me that I was making a mistake. I was listening to the amp without allowing it to have all its glory that High Bias allows. I am a believer now. For critical listening, H is my choice.

Some of the lads believe there is a magical sequence to warming up properly. 33.997 minutes in low, then 17.451 minutes in M. Then 22 minutes in high. I am not one of those. There is no question in my mind that if you were to warm up for 50 minutes in high bias the amp would be ready when you started listening. Segmenting the process just seems a little more trouble than it's worth to me.

Note, I was very happy with my Antileon EVO, but now I use the Apex. Same story.

 

[LL21]

When I was running the Antileon original, Colosseum and then ultimately the Mephisto, I always found the sound was different across all 3 levels. I always preferred H and left it there all the time. There was a 'grain' I found in comparison...subtle but noticeable (to me).

I also had a CJ preamp throughout my time with Gryphons until the very last year or so with the Mephisto when we started with Robert Koda K15EX Preamp...and then ultimately went across to the full Robert Koda system (K160 Ref Monos, also pure Class A 235 Watts into 4ohms).

Hope you enjoy your magnificent Gryphon. They really are special amps. The main ones I have never heard are any of the monos and the Apex series. All of which I understand are just better and better.

 

[Alrainbow]

the class A bias is complex
no matter the selection the amps specs ona given bias is effected by the imp it connects to
including imp curve
next is how loud you play as this makes the amp slide into class A/B faster
a low imp loud is notably effected sooner
but the imp curve can help you predict the tone on a given bias setting

 

[Urbinator]

Its reasuring to hear my listening experiences allign with others. It is am amazing amp and quite a leap from my Kaluga's. High Bias does open up, feeling less restrained. not a huge leap from M but its there. Longer run, I would like to replace the Preamp, but currently the Makua is fully loaded with the Tambaqui and Lupe boards, so any upgrade is gonna be a big leap front end wise once I have regrown the kidneys.

 

[John T]

Your findings match mine. 45 minutes seems a good amount of time to warm up. Switching from one setting to another doesn't seem like a lot of time is needed for it to adjust. The point of the LMH settings is for you to adjust the point where the amp switches from Class A to Class AB. Movies in Class AB are fine. Music when you aren't paying close attention, Class AB may be fine as well. You get all the power the amp can make in any setting. It is just the point where it switches from A to AB that changes. In High Bias mode it is Class A only. If you are listening intently and want the best sound the amp can offer, High Bias is the way to go. Anything less, no big deal. The efficiency of your speakers makes a difference. I used to listen in M mode a lot until a friend convinced me that I was making a mistake. I was listening to the amp without allowing it to have all its glory that High Bias allows. I am a believer now. For critical listening, H is my choice.

Some of the lads believe there is a magical sequence to warming up properly. 33.997 minutes in low, then 17.451 minutes in M. Then 22 minutes in high. I am not one of those. There is no question in my mind that if you were to warm up for 50 minutes in high bias the amp would be ready when you started listening. Segmenting the process just seems a little more trouble than it's worth to me.

Note, I was very happy with my Antileon EVO, but now I use the Apex. Same story.

No Magical sequence, I'm one of the lads. Metal expands and contracts. The certified Gryphon Serviceman who rebuilt my Mephisto Stereo (Great BTW) explained some simple measures regarding bias, startup, and break in. Fascinating guy. He has also been behind some of the designs and changes in Gryphon products. I would never go from startup to High Bias, if the unit was in low, this is no problem. However with a new unit he explained go through the Bias slowly over time. It takes little to no effort to follow a little common sense. If one were to just gradually introduce heat, bias, over time, say for the first few weeks (no set time period) its just a prudent approach. I have always backed it out of High to medium, low, when I am through. But for those of you that don't feel the need, heat it up as quick as you can... The Mephisto with Pandora Pre along with Green Bias, it will kick from Medium into High Bias at 47...

 

[abeidrov]

Below is a quote from the manual:
“When evaluating the sonic effect of the 3 bias adjustment modes, it must be taken into consideration that the Mephisto requires time to settle when bias is changed. (15 min.) Bias may be adjusted with the Mephisto turned on. However, we recommend that bias adjustment be made once and for all during initial installation. If the Mephisto has been turned off using the front panel on/off switch, it will remember the last bias setting. After using the master on/off switch at the rear panel, it will return to its last setting.”

My understanding of the above is that they do not recommend changing the bias setting during a listening session. Seems strange to me, as this goes against their own “Green Bias” mode when using a Gryphon preamp with a Gryphon amp.

 

[John T]

I typically leave the system on in low bias as I listen daily. For me this is not an issue. I was attempting to focus on break in period. My Mephisto Mono's are barely a month old. The serviceman repairs these units. I appreciated the advice he provided. Agreed regarding the Green Bias Cable. I used it only to see where the change occurred. It's not a great concept and makes little sense...

 

[Urbinator]

Thanks for the input guys. Amp is ex demo, so it’s had plenty of time for break in.
My daily is pre amp turned on when I get home, which switches on the amp via the 12v trigger. Later on in anticipation I will switch from L to H and give it 15 minutes.
I have on occasion had it playing in the background and switch over to H. There is a difference within 30 seconds but it takes about 10 to 15 minutes to start to open up. L still sounds pretty good and will wow most, but you can feel the amp is restricted and needs the open road.
I have had it set in H for some UHD films and it’s pretty incredible, but just feels overkill for watching a movie.

 

[JiminGa]

No Magical sequence, I'm one of the lads. Metal expands and contracts. The certified Gryphon Serviceman who rebuilt my Mephisto Stereo (Great BTW) explained some simple measures regarding bias, startup, and break in. Fascinating guy. He has also been behind some of the designs and changes in Gryphon products. I would never go from startup to High Bias, if the unit was in low, this is no problem. However with a new unit he explained go through the Bias slowly over time. It takes little to no effort to follow a little common sense. If one were to just gradually introduce heat, bias, over time, say for the first few weeks (no set time period) its just a prudent approach. I have always backed it out of High to medium, low, when I am through. But for those of you that don't feel the need, heat it up as quick as you can... The Mephisto with Pandora Pre along with Green Bias, it will kick from Medium into High Bias at 47...

Soren?

 

[JiminGa]

Soren?

Hes the best

 

[John T]

Hes the best

Yes he is. One smart cookie! And a cool cat to talk with on a variety of subjects...

 

[HughP3]

I leave the Apex on L when not listening then 45 minutes before hand I switch to H. Its like letting cloudy water settle and become clear. Its a must for me.

 

[LL21]

I leave the Apex on L when not listening then 45 minutes before hand I switch to H. Its like letting cloudy water settle and become clear. Its a must for me.

Agree based on my own experience with Gryphon regarding H.

Interestingly on the Robert Kodas they are always full on...there is a bias switch in the back, but it is not meant to be something where you turn it on at Regular Bias (150 Watts pure Class A)...and then switch up to High Bias (235 Watts Pure Class A). The amp is meant to be just on or off. The bias switch in the back is simply to enable the amp to be set to drive more efficient speakers or harder speakers.

 

[Johan K]

Yes he is. One smart cookie! And a cool cat to talk with on a variety of subjects...

Smart people is usually very fun to speak with !!!

 

[Urbinator]

I would never go from startup to High Bias, if the unit was in low, this is no problem. However with a new unit he explained go through the Bias slowly over time. It takes little to no effort to follow a little common sense. If one were to just gradually introduce heat, bias, over time, say for the first few weeks (no set time period) its just a prudent approach. I have always backed it out of High to medium, low, when I am through.

I'm starting to feel as though the Green Bias is just a party trick and not used by most.
Just from our evening routine, the amp is started in L Bias for around an hour, then switched to High. Later being switched back to L again for around three hours before bed. I have never really bothered with M as the power it consumes does not seem to be much less than H, and I prefer the warm, enveloping sound of H. So in short, I warm up in tick over, go full throttle and then allow it to cool down.
Will have a play with M a little more tonight, maybe I've never given it enough time to settle in.

 

[John T]

I'm starting to feel as though the Green Bias is just a party trick and not used by most.
Just from our evening routine, the amp is started in L Bias for around an hour, then switched to High. Later being switched back to L again for around three hours before bed. I have never really bothered with M as the power it consumes does not seem to be much less than H, and I prefer the warm, enveloping sound of H. So in short, I warm up in tick over, go full throttle and then allow it to cool down.
Will have a play with M a little more tonight, maybe I've never given it enough time to settle in.

For any and all critical listening H is the way to go. If I'm working on a project and just want some music playing I will use M. Most of the time it is in H...

 

[aangen]

I had the Pandora and Antileon Evo. The green cable never came out of the box.
I have the Commander and Apex. Again, no green cable used.
I am not on an energy budget, and the amp heats my room in the cold winters here in Minnesota.

 

[John T]

Agreed, The green bias cable is not a good concept and unnecessary. I did like knowing after I experimented with it where the shift occurred to H...