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The best phono preamp under $1000 (aka the Hagerman Bugle upgrade thread)

mr_petit said:
Interesting. I use a chinese bugle 2 clone (audiowind a-300) with a separate power supply (based upon a module with 7818/7918) and potted ringtransformer (talema style)
I also plan to change the opamps (I currently use LM833), probably do some tests with an OPA1656, and modify the 78xx/79xx for something less noise.
And maybe change out some capacitors and resistors.
But I also maybe plan to add some switching to easy change capacitive and resistive loading.
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Thanks for posting pics. I read that JH's designs were being copied, but this is the first time I got a chance to see one with the cover off. Would be nice to see a schematic. Which op-amps did the Audiowind originally come with? If the basic circuit is the similar, I would definitely try the OPA2210s before the OPA1656 as the latter are FET-based and will likely required a tweaking of the circuit to work optimally. Cheers!
 
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cgallery said:
The Bugle 2 photos show some sort of regulation at the DC input with a transistor, which I don't see in the copy. Maybe the copy is of the first generation Bugle?
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And it appears the RIAA filter is done differently. I think JH has the original Bugle schematic on his "discontinued" page. Might be worth comparing as the components look different enough to not be a Bugle 2/3 clone.
 
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kirk57 said:
What other sub-$1000 phono stages have you compared this with?
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This is best left up to Oranda. I have only compared it to the mani, the original Hagerman bugle2, Pluto, and the inexpensive Chinese made tube amps on eBay loaned to me. I have not obtained any expensive preamps for my system but have compared with some rather expensive McIntosh preamps (not overly impressed but it was not my setup and I don’t know how it was setup).

If you count the built in preamps on my Sansui and Onkyo receivers that’s another pair. In all cases, this is a totally different experience. Those previous ones were as said by another, very subtle. This build has very different sonic response, not subtle, that I don’t believe can be put down in frequency charts and graphs with the tools we have nor simple voltage,current, resistance measurements. It’s hard to describe in words. The opening post describes it best.

I was a skeptical guy up to this point. I’m still wondering how one op amp can vs another can change the delivery this drastically. Same for one single cap swap. I didn’t believe it until I actually swapped them out one at a time; from workbench over to turntable. Sometimes I would do one channel at a time just to see what was what. I think if you try, at this price point, it’s going to be a safe bet.
 
wyn palmer said:
I have to ask, what makes it "the best phono preamp under $1000"?
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I think the WP design might be some serious competition. But I am going to have to have some help and get one built to see.

My goal here is to start on a WP build and get Oranda to help out. Maybe I can ask that Wyn Palmer fellow a few questions too?

I am just going by what I have heard so far. I so wish I had started a build back in 2017 w hypnotad or the original WP design in 2019.

Now, I really think it’s going to boil down to the R,C, and op amp combinations for the over all sound.

I’m betting the WP design has bugle2 beat in a few areas like noise/hum/power supply department. I hate fighting with my cable placement and worrying about hum.

I’m all for learning something new. Once I heard the changes that the op amps could bring about, I was hooked.
 
oranda said:
And it appears the RIAA filter is done differently. I think JH has the original Bugle schematic on his "discontinued page". Might be worth comparing as the components looks different enough to not be a Bugle 2/3 clone.
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I compared it to the Bugle 1 and I think it's indeed it's a bugle 1 clone, not bugle 2.
Bugle 2 has a few different resistor values (4 per side if I looked correctly), so very easy to convert. But the power rail on the A300 is Bugle 2 again. Hybrid? :D

I wonder how important the C4 and C5 (from the bugle2 schematic) capacitors are for the sound, besides having the correct value. I mean they go to ground.
C6 is the only capacitor in the signal path.
 
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oranda said:
Thanks for posting pics. I read that JH's designs were being copied, but this is the first time I got a chance to see one with the cover off. Would be nice to see a schematic. Which op-amps did the Audiowind originally come with? If the basic circuit is the similar, I would definitely try the OPA2210s before the OPA1656 as the latter are FET-based and will likely required a tweaking of the circuit to work optimally. Cheers!
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hagerman.png
The original opamps are LM4562, otherwise known as LME49720. They are 2.7nv/rtHz at 1kHz typical, but the noise for MC due to the 100 ohms and 392 ohms is 2.8nv/rthz so the net input is about 3.9nv so it's pretty darn noisy for anything other than LOMC cartridges.
The OPA1656 is somewhat worse, even A weighted at 4.3nv/rtHz at 1kHz. However as the noise gain of the input stage is 34 with the OPA1656 there would not be any stability issues. The OPA1656 would not be quieter, and would be worse distortion, at least for the input stage, although that is not true for the other stages. The OPA1656 noise for MM would likely be a bit better.
The OPA1220 would be quieter than either of them for MC, still not quiet though, and would definitely be better than the LM4562 for MM. The low offset would make the reduction in swing before clipping at the output of the second stage due to the DC gain of about 1000 for MC essentially negligible. The OPA1220 has a low slew rate, but at phono stage levels that's OK. The gain bandwidth product is a bit low for my taste, but OK.
 
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kirk57 said:
What other sub-$1000 phono stages have you compared this with?
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Off the top of my head, stand alone units I've owned include the Jolida JD 9, Bottlehead Reduction, Micromega MyGROOV, Schiit Mani, Art DJ pre II, and the Realistic 42/2102a. Not part of your question, but I've also had built-in preamps for the Pioneer SA6700 Integrated, the McIntosh MA5100 Integrated, and the McIntosh C35 preamp. I've also demoed a few other popular stand alone units, like the Cambridge Audio 551p. Not in the under $1k bracket, but I recently heard the Nagra Classic Phono. In case you were wondering, the Nagra is superior to anything I've heard... but it's $28k. :)
 
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mr_petit said:
I compared it to the Bugle 1 and I think it's indeed it's a bugle 1 clone, not bugle 2.
Bugle 2 has a few different resistor values (4 per side if I looked correctly), so very easy to convert.

I wonder how important the C4 and C5 capacitors are for the sound, besides having the correct value. I mean they go to ground.
C6 is the only capacitor in the signal path.
Click to expand...

Would you like me to answer this question? It's not as simple as you assume.
 
wyn palmer said:
View attachment 2709005
The original opamps are LM4562, otherwise known as LME49720.
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Thank you Wyn. Sorry for not being clear: I was actually looking for the circuit for the Audiowind... the Bugle 2 circuit I know pretty well and have it linked in my first post. Yes, the slew rate of the OPA 2210 is good enough for phono use. Its a fantastic sounding op-amp, especially in this circuit. Thank you for your very detailed analysis!!
 
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The first 220n cap sets the 318 and 3180us TC. Essentially all frequencies in the audio band between 20 Hz and 2k Hz are subject to whatever distortion the cap creates to a lesser or greater extent.
The 10nF cap sets the 75us TC, and all frequencies from 1kHz on up are subject to its distortion to a lesser or greater extent.
The second 220nF cap sets the LF -3dB cutoff at about 8Hz and will hardly affect the distortion.
 
mr_petit said:
So what about 2x LT1028 on a dip8 converter board?
https://www.analog.com/media/en/technical-documentation/data-sheets/1028fd.pdf
Very low noise, good slew rate, good gain-bandwith product.
Will that work? I'm by no means knowledgeable on this so I'm not sure what to look for.
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Yes, if you can get them to fit. I've used them in other circuits and the LT1028s are wonderful sounding devices. I believe they were used in some older Mark Levinson designs. I'd be very interested in hearing your results if you went that direction. Hopefully Wyn will provide his thoughts on this.
 
mr_petit said:
So what about 2x LT1028 on a dip8 converter board?
https://www.analog.com/media/en/technical-documentation/data-sheets/1028fd.pdf
Very low noise, good slew rate, good gain-bandwith product.
Will that work? I'm by no means knowledgeable on this so I'm not sure what to look for.
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It depends... The data sheet doesn't have much in the way of audio specific information- no distortion for example, and the input current noise would make it a poor choice for MM. Another option might be the LT1115 or the AD797, and the OPA1612 is close (yes, I see that it is disliked) but then the Hagerman will have issues due to the high impedances chosen in the feedback loops and they'll all be terrible for MM- just like the LT1028.
To really do a good job with MC the Hagerman would need a substantial redesign, in my opinion.
 
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