Here is an update to my Pass journey 
In the beginning I was going to go F4 and had all the parts ready for assembly, but decided to go F5 just because it was a lot simpler and less parts. I knew from posts that an F4 would def. need a high gain preamp and looked at Empasse, Pumpkin and BA-3 and am pretty much set on the BA-3 with F4, but I wanted to see first of all with an F5 if 25 watts (50 w into 4ohms???) was enough for my Maggies.
I fired it up for the first time last night and after setting up the bias for an hour or so I sat down to listen to my F5 with hotrodded Mez DCB1. I came away from my 1 hour listening session with this:
1. As suggested in many posts you do need a high gain preamp....I had to max out my DCB1 before I got about 80% to my normal listening level
2. Compared to my (class d) 600 watts into 4ohm amp, F5 was warm, little less bass and I felt nothing was lost. What was gained was musicality, some passages had rhythm that immediately caught my attention.
In another thread I started "feeding BA into F4" .... I am now thinking I should get that BA3 gain stage and put that in my F5 or like TimBarnes did, put it into an external chassis for flexibility so that when I build my F4 I could easily swap it in and out.
I do want to thank Mr Pass, all those that have come before me and posted and a big shout out to 6L6 (Jiim) for guiding me through my build. It fired up first time without any smoke or buzzing
In the beginning I was going to go F4 and had all the parts ready for assembly, but decided to go F5 just because it was a lot simpler and less parts. I knew from posts that an F4 would def. need a high gain preamp and looked at Empasse, Pumpkin and BA-3 and am pretty much set on the BA-3 with F4, but I wanted to see first of all with an F5 if 25 watts (50 w into 4ohms???) was enough for my Maggies.
I fired it up for the first time last night and after setting up the bias for an hour or so I sat down to listen to my F5 with hotrodded Mez DCB1. I came away from my 1 hour listening session with this:
1. As suggested in many posts you do need a high gain preamp....I had to max out my DCB1 before I got about 80% to my normal listening level
2. Compared to my (class d) 600 watts into 4ohm amp, F5 was warm, little less bass and I felt nothing was lost. What was gained was musicality, some passages had rhythm that immediately caught my attention.
In another thread I started "feeding BA into F4" .... I am now thinking I should get that BA3 gain stage and put that in my F5 or like TimBarnes did, put it into an external chassis for flexibility so that when I build my F4 I could easily swap it in and out.
I do want to thank Mr Pass, all those that have come before me and posted and a big shout out to 6L6 (Jiim) for guiding me through my build. It fired up first time without any smoke or buzzing
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Fantastic news! Glad to hear everything is working.
A couple thoughts -
Gain: Putting a BA-3 FE in the F5 will be way, way to much gain. As a stand-alone preamp, however, would be fine. You will need it for the F4 anyway...
But - have you considered changing the gain of the F5? It's really simple, change the feedback resistors (currently the (4) 100ohm 3W in the center of the PCB) to 150ohm or 220 ohm. This will reduce the overall feedback increasing gain. You would need less knob on the B1 for a given output level.
Anyway, in the time being, enjoy your new amp, listen to all your music again and hear things you haven't before.
A couple thoughts -
Gain: Putting a BA-3 FE in the F5 will be way, way to much gain. As a stand-alone preamp, however, would be fine. You will need it for the F4 anyway...
But - have you considered changing the gain of the F5? It's really simple, change the feedback resistors (currently the (4) 100ohm 3W in the center of the PCB) to 150ohm or 220 ohm. This will reduce the overall feedback increasing gain. You would need less knob on the B1 for a given output level.
Anyway, in the time being, enjoy your new amp, listen to all your music again and hear things you haven't before.
That did the trick Jim. I went from 6 o'clock back down to 1 o'clock on the preamp.
It was worth driving 40 miles to get 220 ohm 3W resistors
K so in layman's terms....F5 is 25 watts into 8 ohms and maybe 50 watts into 4 ohms...so with the gain from the DCB1 + the added gain to the F5 I have now the same listening levels to my previous 600 watt class d amp. How is that possible?
It was worth driving 40 miles to get 220 ohm 3W resistors
K so in layman's terms....F5 is 25 watts into 8 ohms and maybe 50 watts into 4 ohms...so with the gain from the DCB1 + the added gain to the F5 I have now the same listening levels to my previous 600 watt class d amp. How is that possible?
Agree, I never did utilize all of its power. I spent another 4 hours listening yesterday and I love how the brightness of the previous amp has gone away. The only thing I am missing is the bass, but it could have been over emphasized?
What stands out for me with this F5, is the musicality. Don't know how to explain it - my prev amp just played the music and loud. This F5 plays it at a relaxed but emotional level. I am hearing a little more music/instruments/notes in heavier passages.
I am so glad it worked out well, I really love my Maggies and would have had a hard time selling them.
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Zen Mod, your post made me realize that I still have a wirewound resistor at my speakers to tame the brightness of high frequency - mainly because of the class d amp. I know that It had some impact (little) on sonics but I should pull that out and listen again. The problem with Maggies is that it requires space to sound its best and an inch hear or there will throw it off - those with Maggies will understand what I am saying. So now that I have the perfect location, I have marked my carpets so if I have to move them I know where to return them
If I have those resistors I'll certainly try that.
If I have those resistors I'll certainly try that.
oh good. im so glad its working out for you.
i bet you are hearing new things. maggies are nice speakers, one of my favs.
if i had the room to set them up the way they need to sing id get some in a instant!
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