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Phono Preamp? Tube or SS


JohnJ

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I spoke too soon on the iTube2. Changing a record last night and didn't turn the volume down to 0 or 1 and I could hear humming. Might accept that being a tube thing but the glowing wordy reviews and the page at the iFi site state absolute silence when not in use. Switched cables, changed where it was plugged in, troubleshooting couldn't resolve it. Plan C in action now! I'm not joking about how good the sound was compare to playing those lps without it. Darnitt.

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20 minutes ago, Full Range said:

Humming is most likely

earth 

bad wire connection in any line 

dry solder 

rca cables or plugs 

 

Yessirre! That's why I checked what I could that could have been on my end. Took those RCAs off and used the new unused ones I have in a box from all the new stuff. Made no difference, put the good ones back on and I'm back where I started.:huh:

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Yep, I've got an imagination! Think I tried every variable except moving that 500lb cabinet into a different room. Nothing new except for the two different things I tried this week to improve the already decent phono. The AudioQuest Black Mamba II RCAs I've got have been running from the tt and the cassette deck. They're dead quiet RCAs I love `em. Back on the tt now, it's good to go. I picked up a "line conditioner" earlier this year and have the stereo all plugged into it. It's got separate output circuits (Furman pfi15), tried changing that and removing things. Thought maybe something weird between the adaptor/ps thingy for the iTube2 and the furman so I plugged it into the wall also. No change there either. Only electrical troubles we have here is running the microwave and the toaster (on same outlet) at the same time! Trips the surge protector there. As far as rf, the CXN operates off of the wifi here, that will not change, other stuff will have to put up with that.

Even integrated the single set of cables that came with the unit into the circuit.

 

Best thing I can think of was it did not want me to use the +9db that I did value, and you know what, that is the one thing I did not change, didn't try it with 0db gain. Whatever it was must have been internal to the new thing that I put in the signal path.

Next up will have a physical post for tt ground wire to connect, think that's better than the component chassis I had it on for this iTube2. The cassette deck is what the ground has been attached to for months without issue

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OK folks if you're interested in an update, especially you @Full Range I have defined the problem.

 

It is my turntable, an audiophile website in the UK (I think) must have been told a fallacy about the AT-LP5 by the AT eu people. This authors mentioning of how he was told the preamp switched out of the signal path at that site and forums is what cemented my decision. I'm not faulting that gentleman at all, prefer to believe that he was repeating what he'd been told. When I searched for the impedance spec for my turntable it pulled up his review on google and I saw it again 

 

After an impressive sounding and more expensive Pro-Ject Tube Box DS here made a lot more buzz when the needle was raised I called AT USA. It raised the S/N ratio a lot more too! I had it set at its mid level.

I was told by an Audio Technica tech here that the tt does "not take the internal preamp out of the signal path" on my AT-LP5. That makes pairing it with a compatible preamp troublesome jut like the AT-LP120 did. f$#*   %e

BOOM!

Replacing the tt & cart is too much $$ right now. I will return an iFi micro iTube2 to my system because the amount of "buzz" it made was something I had to actively listen for and turn it up a little to discern with nothing playing. That thing sounded sweet, has three profiles to match many lps and costs a bill less.

 

I feel that I've committed a socio-economic crime this week, but rationalizing..... darnitt I've contributed to our economic recovery too!

I've got a headache.

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Hey @Full Range If I recall correctly you said that you made that incredible tonearm on your rad turntable..correct?

Seriously thinking of "removing" that preamp permanently from the signal path. My warranty is up in a week, resale value isn't enough. a Rega 3 or Pro-Ject Classic isn't cheap and i'd still have to pickup another phono preamp!!!! Top it off if it wasn't for that I'd still be pleased with this chunky kinda masculine appearing tt. 

Thinking F it, remove that from the circuit, practice soldering again on something benign with wires in it. when I'm comfortable with it - do it.

Asking, ot obviously if I took pics of the guts if you think you would be able to help me identify that preamp circuit.

 

**googled found a teardown review. Had an offer of $150 for it. Ticked off and will consider.

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30 minutes ago, JohnJ said:

Hey @Full Range If I recall correctly you said that you made that incredible tonearm on your rad turntable..correct?

Seriously thinking of "removing" that preamp permanently from the signal path.

 

My Garrard 401 turntable upgrade 

I remade the plinth using mechanical engineering principles 

The tone arm was purchased from TransFi Audio in the UK  - http://www.trans-fi.com/terminatortonearm.htm

 

Its not hard to wire the tone arm wires direct to RCA plugs 

Just get the colours correct for correct R/L channel 

 

Its best however to secure the RCA sockets in natural timber and under the TT - If you click onto the link above you will see an example of what I’m trying to convey 

 

 

CartWiring.gif

 

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I know that took some effort to get it calibrated after constructing.

I won't be doing that, but was thinking of disconnecting the amp internally. That tear-down on youtube shows a stacked pcb where the switch is on the back, so couldn't see the preamp. All in time. It sounds decent as is, I've got that bug and want it better. Sounds great with that iTube2 will hook that up again and chill.

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I've got vta again and azimuth now, never had that on a tt before. Styli have always looked perpendicular to the cart when I got them.

Don't care for the shiny on the 1Xpression but I'll be okB) Should be leaps & bounds better for this discerning (picky) fella.

 

I've seen those uTurn since I started refurbishing the stereo last fall, they do look nice!

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