8 Channel, 3U NEVE 1073 completed

[sr1200]

Ive got pots on all of mine. Dont really notice any noise per se but my guess would be it depends on the quality of the pot. And ps, being able to push that gain stage is awesome and well worth any noise trade off.

 

[critterkllr]

Ive got pots on all of mine. Dont really notice any noise per se but my guess would be it depends on the quality of the pot. And ps, being able to push that gain stage is awesome and well worth any noise trade off.

Thanks. I have a bunch of PEC 5K log pots and it would be easy to just hook one up I guess. I'm just getting nit picky in the planning stage before actually hearing it 

 

[MicDaddy]

FWIW I also put pots on all 8 of mine.  They wouldn't be the same without them.  Highly Highly recommend the trimmers, like sr1200 says being able to push the gain and pull the trim back brings out something, how do we say like Mr Neve, 'Sweet'  8)

The trimmers really make them more versatile for me.

Chose some high quality conductive plastic pots linked earlier in the thread or similar.  I think they cost me some ~$8/ea and feel smooth.  I cannot comment on added noise, I would assume this comment is relating to the distortion which I concur.  Again they really sound something sweet when driving the front end with full ~full gain and the trimmer pulling the output level back.

 

[desol]

Yep. Still glad that i etched out spots on the front panel for trims... 

 

[tomas1808]

Any reason not to use a rotary switch instead of a trim pot?

 

[critterkllr]

Can anybody recommend a suitable transformer alternative to the 62085-P2S02 listed in the bom? I've had 2 on backorder from Digi-Key for a month and just finally received an estimated lead time of December 19th. I have 2 x EZ1290s (plan on having 4 eventually) and have the JLM ACDC. Everything is ready to go waiting on the transformer. I'm a bit of a noob when it comes to PSUs.

Should this do the trick? http://www.digikey.com/product-detail/en/70085K/TE70085-ND/251503

 

[Chrome Heart]

Can anybody recommend a suitable transformer alternative to the 62085-P2S02 listed in the bom? I've had 2 on backorder from Digi-Key for a month and just finally received an estimated lead time of December 19th. I have 2 x EZ1290s (plan on having 4 eventually) and have the JLM ACDC. Everything is ready to go waiting on the transformer. I'm a bit of a noob when it comes to PSUs.

Should this do the trick? http://www.digikey.com/product-detail/en/70085K/TE70085-ND/251503

http://www.hammondmfg.com/182.htm

 

[critterkllr]

Can anybody recommend a suitable transformer alternative to the 62085-P2S02 listed in the bom? I've had 2 on backorder from Digi-Key for a month and just finally received an estimated lead time of December 19th. I have 2 x EZ1290s (plan on having 4 eventually) and have the JLM ACDC. Everything is ready to go waiting on the transformer. I'm a bit of a noob when it comes to PSUs.

Should this do the trick? http://www.digikey.com/product-detail/en/70085K/TE70085-ND/251503

http://www.hammondmfg.com/182.htm

Maybe I should have mentioned this is my first time building a power supply and have no idea how to calculate/design around a transformer. None of the hammond transformers I've found have the same specs as the transformer listed in the bom 62085-P2S02. Specifically, the Hammond's are all at 24V and the Amveco is 22V. Also, the Hammond's have dual secondaries, would I just wire it up with one of the secondaries disconnected? Is it a better choice than the pcb mount Amveco in my link?

 

[Chrome Heart]

Can anybody recommend a suitable transformer alternative to the 62085-P2S02 listed in the bom? I've had 2 on backorder from Digi-Key for a month and just finally received an estimated lead time of December 19th. I have 2 x EZ1290s (plan on having 4 eventually) and have the JLM ACDC. Everything is ready to go waiting on the transformer. I'm a bit of a noob when it comes to PSUs.

Should this do the trick? http://www.digikey.com/product-detail/en/70085K/TE70085-ND/251503

http://www.hammondmfg.com/182.htm

Maybe I should have mentioned this is my first time building a power supply and have no idea how to calculate/design around a transformer. None of the hammond transformers I've found have the same specs as the transformer listed in the bom 62085-P2S02. Specifically, the Hammond's are all at 24V and the Amveco is 22V. Also, the Hammond's have dual secondaries, would I just wire it up with one of the secondaries disconnected? Is it a better choice than the pcb mount Amveco in my link?

I thought the Amveco had dual secondaries. I see a couple of 22V torroids on the Hammond list that look like they would work. Maybe Im wrong. It wouldnt be the first time.
http://www.hammondmfg.com/pdf/182%20Insert.pdf

 

[wimmy7986]

Awesome!  Thanks for pointing out the hammond options.  I think I've narrowed it down to this model... http://www.mouser.com/ProductDetail/Hammond/182L12/?qs=%2fha2pyFaduhkZsoALO1xLH8m%2fA88eyezwSWKx62QmIo%3d

There's also a 30 VA option

Can anyone confirm this will work for one or two channels?  I'm a noob when it comes to power transformers, and just want to be extra sure...  Thanks

 

[critterkllr]

Awesome!  Thanks for pointing out the hammond options.  I think I've narrowed it down to this model... http://www.mouser.com/ProductDetail/Hammond/182L12/?qs=%2fha2pyFaduhkZsoALO1xLH8m%2fA88eyezwSWKx62QmIo%3d

There's also a 30 VA option

Can anyone confirm this will work for one or two channels?  I'm a noob when it comes to power transformers, and just want to be extra sure...  Thanks

For one or two channels, Digi-Key has this in stock: http://www.digikey.com/product-detail/en/62075-P2S02/TE62075-ND/299875

Not sure if it will work, but it seems like it should.

 

[Chrome Heart]

Awesome!  Thanks for pointing out the hammond options.  I think I've narrowed it down to this model... http://www.mouser.com/ProductDetail/Hammond/182L12/?qs=%2fha2pyFaduhkZsoALO1xLH8m%2fA88eyezwSWKx62QmIo%3d

There's also a 30 VA option

Can anyone confirm this will work for one or two channels?  I'm a noob when it comes to power transformers, and just want to be extra sure...  Thanks

For one or two channels, Digi-Key has this in stock: http://www.digikey.com/product-detail/en/62075-P2S02/TE62075-ND/299875

Not sure if it will work, but it seems like it should.

795mA seems a bit on the light side to me. The 62085 in the BOM is 1.13A. I would opt to go higher than lower.

 

[critterkllr]

Awesome!  Thanks for pointing out the hammond options.  I think I've narrowed it down to this model... http://www.mouser.com/ProductDetail/Hammond/182L12/?qs=%2fha2pyFaduhkZsoALO1xLH8m%2fA88eyezwSWKx62QmIo%3d

There's also a 30 VA option

Can anyone confirm this will work for one or two channels?  I'm a noob when it comes to power transformers, and just want to be extra sure...  Thanks

For one or two channels, Digi-Key has this in stock: http://www.digikey.com/product-detail/en/62075-P2S02/TE62075-ND/299875

Not sure if it will work, but it seems like it should.

795mA seems a bit on the light side to me. The 62085 in the BOM is 1.13A. I would opt to go higher than lower.

I know it's been discussed before, but I talked to Joe at JLM and he said one should power 4 with phantom power. I picked one up and am powering 2 with it.

 

[desol]

You want 350-500mA per channel.

 

[Harpo]

You want 350-500mA per channel.

Seems a lot over the top. A 1290 will draw 125mA of DC current. 250mA for two. Add current draw of enabled +48VDC phantom rail 2 Ch.* worst case 14mA * form factor 4 from voltage doubler circuit, current draw of voltage regulators network and some status LEDs on top, the 795mA AC current of the Amveco 62075 with paralleled secondary windings seems sufficient for two channels, delivering up to 795mA AC/form factor 2.3 from halfwave rectifcation=345mA DC. As always YMMV.

 

[MicDaddy]

A 1290 will draw 125mA of DC current

  I can't recall exactly the value, but I want to say the inrush was quite a bit higher.

 

[desol]

It was a while ago, but I remember blowing a 2.5 amp fuse upon powering up my 8 channels. I decided
to measure the inrush current...and it clipped about 3.2 amps dc....then settled at around 800 mA.

Threw in a 3 amp fuse...no more problems.

 

[critterkllr]

It seems like a lot of guys don't have access to an oscope and signal generator. Did anybody do a before and after to test the difference between biasing correctly and the ballpark voltage listed? I hooked mine up before because I let somebody borrow my oscope. It sounded good before, but after biasing seemed to sound wider with more of the signature pronounced chunky low mids. Sound went from very Neve inspired to Neve.

Just wondering if others could share their experience so people without a scope could potentially make some adjustments using their ears.

 

[Chrome Heart]

It seems like a lot of guys don't have access to an oscope and signal generator. Did anybody do a before and after to test the difference between biasing correctly and the ballpark voltage listed? I hooked mine up before because I let somebody borrow my oscope. It sounded good before, but after biasing seemed to sound wider with more of the signature pronounced chunky low mids. Sound went from very Neve inspired to Neve.

Just wondering if others could share their experience so people without a scope could potentially make some adjustments using their ears.

Page 84 of the thread had a discussion on that topic recently.

 

[critterkllr]

It seems like a lot of guys don't have access to an oscope and signal generator. Did anybody do a before and after to test the difference between biasing correctly and the ballpark voltage listed? I hooked mine up before because I let somebody borrow my oscope. It sounded good before, but after biasing seemed to sound wider with more of the signature pronounced chunky low mids. Sound went from very Neve inspired to Neve.

Just wondering if others could share their experience so people without a scope could potentially make some adjustments using their ears.

Page 84 of the thread had a discussion on that topic recently.

Checked the thread a few times for the audio difference between biased and under/over biased and can't find anything.

One more question. What are the different specs on using a 5k or 10k pot for trim? -20db, +/-10db, etc? Is it passive with unity turned fully clockwise, or active like some Neves where unity is at the center?