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

Quick question: are there differences between the various versions of a given chip besides SOIC and DIP? The retailers usually have several product numbers for the same numbered chip that appear identical. Some versions are a few pennies more than others.
 
saltytown said:
Quick question: are there differences between the various versions of a given chip besides SOIC and DIP? The retailers usually have several product numbers for the same numbered chip that appear identical. Some versions are a few pennies more than others.
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Yes, there can be. You just need to read the datasheets to find out.

For example, the NJM2068DD is a low noise selected version of the NJM2068D.

"The D-Rank type products(NJM2068DD/LD/MD) have specified maximum limits for equivalent input noise voltage."
 
saltytown said:
Quick question: are there differences between the various versions of a given chip besides SOIC and DIP? The retailers usually have several product numbers for the same numbered chip that appear identical. Some versions are a few pennies more than others.
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Depends on what you’re looking at. Oranda has been testing out more models for the bugle and can tell you what works best.
 
I'm following his most recent suggestions. I was referring to chips with the same basic number, like 1358, that also have a few varieties of the same chip with different suffixes after the numerical designation.
I don't know if selecting a certain sub-category of a given chip makes a difference for the purposes we are discussing here.
 
saltytown said:
I'm following his most recent suggestions. I was referring to chips with the same basic number, like 1358, that also have a few varieties of the same chip with different suffixes after the numerical designation.
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Those suffixes are usually documented in the documentation for the chips themselves. They often have to do with pretty mundane things like the sort of plating on the leads.

When ordering I typically look at the stock levels of the various varieties and buy whatever everyone else seems to be buying.

It can be pretty easy to tell based on inventory levels at places like DigiKey and Mouser.
 
cgallery said:
Those suffixes are usually documented in the documentation for the chips themselves. They often have to do with pretty mundane things like the sort of plating on the leads.

When ordering I typically look at the stock levels of the various varieties and buy whatever everyone else seems to be buying.

It can be pretty easy to tell based on inventory levels at places like DigiKey and Mouser.
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Good tip, thanks.
 
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Here’s the LT1358 IN8. Has the legs so no browndog adapter needed.

It will lower the noise floor if you put in the OP2210 in U2 position. You also should look at the Muses02 as it does very well for me in the U4 position. It doesn’t need the adapter either.
 
Wee update: I managed to get a 1358 installed without frying it by wearing a little wrist strip attached to ground at an outlet. All I can say is Oranda nailed it. The sound is way less compressed and more 3D. Next up is the middle position opamp. This can wait. I'm digging the sound of the MC with the upgraded power supply and the 1358.
 
saltytown said:
Wee update: I managed to get a 1358 installed without frying it by wearing a little wrist strip attached to ground at an outlet. All I can say is Oranda nailed it. The sound is way less compressed and more 3D. Next up is the middle position opamp. This can wait. I'm digging the sound of the MC with the upgraded power supply and the 1358.
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Was it a new 1358? Glad you got it going! Hope you get the U3 upgrade sometime and let us all know what you find.
 
Yes, I started over with a new 1358. At some point I'd like to drop in a silver mica cap. However, I'm schematic challenged and can't decipher which caps on the board correspond with those in the schematic. The MC is subtly different from the 3.
 
saltytown said:
Yes, I started over with a new 1358. At some point I'd like to drop in a silver mica cap. However, I'm schematic challenged and can't decipher which caps on the board correspond with those in the schematic. The MC is subtly different from the 3.
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If you can take a pic of your MC we should be able to help you. It should be the middle cap of the 3 caps on right and left of the middle opamp in the u3 position. They are the blue caps on the right and left on the board in my pic. In front of the biggest cylinder ZN caps I installed. I hope this helps.

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I don’t know what the layout of the MC looks like but I hope it’s similar enough that you see the 3 caps, c4,c5,c6 on the left and right edges of the board along the outside of their respective op amps. Jim’s design keeps pathways short and neat to help keep noise from outside sources to a minimum. My big ZN’s are more sensitive than I thought they would be.
 
I lifted this pic from Jim's website. As you can see it looks quite different from the 3
 

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I am not able to zoom in enough with that resolution. You are correct that the layout is different by quite a bit. You are going to need to use the schematic and follow it out. The caps are so close together on that board that I don’t know if you can fit them on there.

I wouldn’t want to try to make them fit. Especially if they are the ones right above and below the opamp in the pic. I don’t want to say that those are the ones but from the pic and bugle design it looks like those are the only ones that are paired with each opamp for the 6 caps used.
 
Thanks for your advice. Wiser heads will prevail. I was concerned with how close the caps are to the opamps as well. Probably best to just be happy with tweaking some opamps. I'm happy with the sound now. I'll mess with the middle opamp at some point and report back.
 
You can always get a Bugle3 pcb if they still have them. The spacing is tight but still doable if you’re not as bad as me with soldering.
 
I'm too lazy to start from a blank PC board. I didn't relish sourcing all the parts for a scratch built Bugle.
Well, a little voice in my head compelled me to pull the middle opamp and replace it with a 49723MAX. As Oranda implied the choice for the middle opamp is largely system dependent. The 49723 was a total bust in my system. The lead vocals became recessed in the mix and backing vocals took on a homogeneous quality. With the 4562 in place I could pick out individual harmony singers.The bass became more bloated.
Back went the 4562 and the sun is shining again.
One note: the plug the Jameco power supply is loose in the socket of the MC.
 
saltytown said:
One note: the plug the Jameco power supply is loose in the socket of the MC.
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I have had the same experience with my recent build and it turns out that one power supply is a little loose. The other is fine. I wouldn’t worry about it if it is working okay. It’s not like you need to unplug it every day or anything like that?
 
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