I'm hoping that the 2x 47pF miller cap on the LF03s (which is stable in the MyRef Rev C) will also be stable in the lf03d (2x LF03s) plugged into a MiniRef 3886, with no other changes. I'll find out only by trying. If it is stable in a MiniRef 3886, it will most probably be stable in a MiniRef 1875 also, but that needs verification in a real board, as always.
Quick newb question. Plse be gentle! I have just finished building the rev c and fired up okay. The relay kicks in just fine at start up no pops or clicks but I get a slight pop at power off. Is the relay not meant to disconnect the speaker at power off?
That's fine - the relay won't release immediately on power off, as long as there's some reasonable rail voltage and the output DC is within limits. This can allow an audible pop on power-off.
Coolio and thanks for the prompt reply. Just mentioned as I also built a couple of the ebay XY LM3886 module jobbes for an AB comparison. The associated XY loudspeaker protection modules disconnects on power on and power off,. No transient pops or clicks at all. Thought it was prob not a feature of the rev c protection but just thought I'd check all is well.
Using the Galaxy 388 case with this
Anyone done it? Galaxy 388 w 10mm front I'm wondering if the "quasi-heatsinks" are adequate for this amp
I'm using the MyRef Rev C, layout v 1.2 by Russ White (pcb is dated 9/1/2006) with 2 Antek AN-2225 toroidals for power
Anyone done it? Galaxy 388 w 10mm front I'm wondering if the "quasi-heatsinks" are adequate for this amp
I'm using the MyRef Rev C, layout v 1.2 by Russ White (pcb is dated 9/1/2006) with 2 Antek AN-2225 toroidals for power
It depends on how difficult are your speakers to drive...
With 89dB sensitivity and up loudspeakers it should work, it did with my Infinity Alpha 40 for 2 years.
Cool, thanks Clave. I'm using the bargain-basement old-style Insignia bookshelf speakers from when they used to be good, the NS-B2111. They're 8ohms, 90dB
No worries.. I trust Danny's opinion and he says they are "nice".
Best of luck modding!
Where can i find the latest and greatest bom for the myef. I have linuxguru's 1.4 boards, planning to use revc compensation. Trafo is 22v and I am planning to use both 4 and 8 ohm speakers.
Please suggest good speakers for myref. I'm thinking of reference speakers (the purist style). Do I need an active subwoofer? Or can this thing drive a 3 way using a passive crossover? Ideally I'd like to go the DIY way and build them myself. But feel free to suggest if I can get hands on something readymade. Thanks 🙂
No problem to drive 3 way speakers but is preferable to have not too low impedance and fairly high sensitivity. I would say minimum 4 ohm impedance and 88dB sensitivity.
I have been building and buying speakers since the mid 60's. The Sunflowers are the best I have owned and are a super price/performance value. They are not the most efficient but when matched with the MyRef FE only volume attenuation is needed for most situations. Just yesterday I was considering adding the Carver Sunfire Sub clone (68 pound magnet) that hasn't been used for almost a year - but that was only because a got a new cathedral pipe organ recording and was curious about determining whether there was anything (mostly physical) under the Sunflower output. Can't be much cause as I've reported often, the FEs and Sunflowers can rattle the coffee cups in the cupboard three rooms away.
The only other top end speakers I'd consider building/owning are the Statements or Jim Holtz's latest - The Finalists. I actually have all the panels for a set of Mini Statements cut but haven't bought the drivers yet. Might sell that as a flat pack and give the Finalists a try.
The only other top end speakers I'd consider building/owning are the Statements or Jim Holtz's latest - The Finalists. I actually have all the panels for a set of Mini Statements cut but haven't bought the drivers yet. Might sell that as a flat pack and give the Finalists a try.
So finally I bought a readymade myref over ebay (the classic lines diy amp) and 4 double-sided stereo PCBs. I don't have the power supply yet. Will order the Xfr winding today. Very eager to test it. I initially just wanted to order the PCBs but when I reached the local electronics shop, that guy was very fussy and availability of parts was highly limited. It's less of DIY electronics today and more of plug-in plug-out and throwaway electronics today.
One thing I can tell from the first looks is that the specs have been followed closely and the parts seem to be good, audio grade unlike the generic throw away passives from my local shop. Costed USD 52 (amp) + USD 30 (DHL shipping) + USD 30 (customs)
Anyways I built my first amp with an LA4440 and a DIY bookshelf 3-way speakers. And I've extracted the best of its potential. But that was made in 1995 and was progressively upgraded over time (you know pocket money and all. Today I'm salaried). And I know how much a pain it is starting from sq. one and then fine tuning it, blowing away ICs and desoldering and resoldering it on a general purpose PCB. I trust DIY more than a ready-available branded amp. That's because DIY is made for my, by me of the parts that I choose. This time I've got a ready PCB of something that all (most) audiophiles in this thread have vouched for and my only job is to assemble the big blocks and tinker with it to fine tune if required. I'm also planning to go for Dayton Audio RSS390HF-4 15" Reference HF Subwoofer. Mids and tweeters haven't been finalized. I'm here to bug you guys. And thanks Mauro; you're my hero.
More updates coming...
View attachment 388950
One thing I can tell from the first looks is that the specs have been followed closely and the parts seem to be good, audio grade unlike the generic throw away passives from my local shop. Costed USD 52 (amp) + USD 30 (DHL shipping) + USD 30 (customs)
Anyways I built my first amp with an LA4440 and a DIY bookshelf 3-way speakers. And I've extracted the best of its potential. But that was made in 1995 and was progressively upgraded over time (you know pocket money and all. Today I'm salaried). And I know how much a pain it is starting from sq. one and then fine tuning it, blowing away ICs and desoldering and resoldering it on a general purpose PCB. I trust DIY more than a ready-available branded amp. That's because DIY is made for my, by me of the parts that I choose. This time I've got a ready PCB of something that all (most) audiophiles in this thread have vouched for and my only job is to assemble the big blocks and tinker with it to fine tune if required. I'm also planning to go for Dayton Audio RSS390HF-4 15" Reference HF Subwoofer. Mids and tweeters haven't been finalized. I'm here to bug you guys. And thanks Mauro; you're my hero.
More updates coming...
View attachment 388950
How well is the LM1036 tone control suited for this circuit? Additionally how does LM1036 work if I tune it to compensate for the F3 fallout of the sub-woofer? Is it possible?
It sounds like you are aiming for a multi-channel system - possibly home theater. Is that correct? If so, that's a different path/implementation than the usual full spectrum (no tone controls) stereo setups most discussed with a MyRef at the center.
I'm going for a true reference system. myref amp + 3-way stereo speakers. I intend to use LM1036 to equalize for the F3 of the sub (or anything else that I may want to tune with tone controls). The controls will most probably be fixed to a certain value so there's no user control except the volume.