QUESTION-Phono-Preamps//Inboard vs. external???

[mcgjohn]

@doctor fuse is correct. Have bought two of the EAR clones, plus have a real EAR. They sound identical. Pretty tough to beat the clones until you get north of a kilobuck.
The other one worth considering is the clone of the Marantz 7 phono stage. There are several versions offered. Be sure you get the one with the 6X4 rectifier tube in the front end and the fully shielded power transformer. either will be a def step up from any built in phono stage unit.

 

[mcgjohn]

I like the EAR 834 clones Do you think they are good deal at the price?

https://www.ebay.com/itm/192265300740?_trkparms=ispr=1&hash=item2cc3e7ab04:guUAAOSwhURZggYR&amdata=enc:AQAFAAACcBaobrjLl8XobRIiIML1V4Imu%2Fn%2BzU5L90Z278x5ickkfKe2vUidqHRg3XM2X2xOVAbu4hE%2Bz6NFMT3Bi2y6lOghMAa56JszRXPrDjp%2BI0t8BIrpPI%2FhCg8mOzwbQAvkXFitbvXoKGyFEipwU9JgRRMXIgVLBpKQMnaTSr6FMG0iuvLN2K9%2BsFaW6ZyRMo6MaDdShVN4q8Nq0ZmUJp89MbViZPvxq0rvPyuVfrMYGNhTF%2FwrWSELcL3isB3RCFFzgRKO0xrvKQY3qMxBFveEqSYxW5CEqV2gCpElaZlZ5YrQXtQXiUFU42tfST5%2B1VzXQcUIqYM0fOyI3l3tNVbhZoEu5Dg81FnmaZK3LFOIT6i1FbQns6bOaDyRXRsGZlxZOaX38ERDAIU7a0Tr5vjqezrO2iiIbqz1P227V2%2FbZUtVrpI8C4JOCLbDQQ0Dkm%2BiGsbXHKK17V2b4wztIiOQwrYr2qAHQnJ%2FQGo5SZXNpPbcu2qLzK190T9uf9KoJaCIubEOU2ImyYWeF18HHRU8Wms7wIqfMVC%2Bsb5HxH%2F4Zrkr9n%2BboXsbey2N6M0NXg%2F%2B1OYzmudaC3UcSjwJRFIxyli1hIp5pKZOWifhOfFUXW%2FYeks59qBM0ub771LkT1wcZtAIXNxxJu2So%2ByfV%2FCsVuSUKkSLADqN6x64vOGIhn3VXIWo5%2BpVsoabxFnVynEMNyqvr%2BEY8vmKJw1fikPv842svp6sWzExpCTupjGNv%2FlJ9VeuJaTr08sobNnzbEy2JjwZUECCz%2F4ofhUawkUPbmf6HXRwdOOINajcVRpqL6v%2FUAchhFBFm3KizifbZNixKQ%3D%3D|cksum:19226530074068be0de2cabd40ee95e027142e6820b6|ampidL_CLK|clp:2334524


I assume I need the 115 volt unit for USA? IS this true? How are the Shuguang 12AX7 tubes.??

Steve.

Yes, that is one of the clones, They do sound good, amazing sound for not a lot of dollars spent. The other is more of a true clone from Doukmall, has a case that is a closer copy of the original EAR. But you would not go wrong getting this one.
I have bought a couple of these exact models you posted the link to. Changed the RIAA EQ curve to NAB and use it for a tape head playback unit. One of the best open reel tape playback units I have heard until you get north of the 1.5K mark, then there are some better units out there.

 

[pyoung272]

Regarding the ear 834 clone, the one that the op linked to, it comes with shuguang tubes. Are these any good or is it better to buy the units w/o tubes and supply my own? Price difference is around $30. Like the OP, I am considering another phono preamp (currently using 1st generation project tubebox) and this ear clone is one I am considering.

 

[doctor fuse]

Regarding the ear 834 clone, the one that the op linked to, it comes with shuguang tubes. Are these any good or is it better to buy the units w/o tubes and supply my own? Price difference is around $30. Like the OP, I am considering another phono preamp (currently using 1st generation project tubebox) and this ear clone is one I am considering.

I got mine without tubes, so cannot comment on the quality of the Shuguang tubes.

I hace rolled several combos, including Bogen/Mullards, Rogers, Electrohome, and JJs, without hearing much if any difference. Note that tube matching is not necessary in this design (12AX7 tubes are basically two tubes in one).
If you have 12AX7 tubes lying around, def get it without tubes. If you don't, expect to pay more than $30 for 3 tubes.

 

[StepheK]

In mine, the low noise 7025 were clearly better than the 12AX7 tubes I tried.

 

[pyoung272]

Thanks for replies regarding tubes for the ear 834 clone.

 

[mcgjohn]

Both of mine came with shuguang tubes. They are ok, but was not long before I sub'ed in some PSVANE T-IIs. On these units (as well as the orig EAR), adding a film bypass cap to the main PS filters really helps clean things up. Not a huge deal to do. Carefully drill an 1/8 inch hole next to the power supply caps to run one of the cap leads through.

 

[pyoung272]

mcgjohn, I believe you have the doukmall 834 clone. I notice this unit has a volume control which is unusual for a phono preamp. Is this volume control useful? Can it be bypassed?

 

[doctor fuse]

Both of mine came with shuguang tubes. They are ok, but was not long before I sub'ed in some PSVANE T-IIs. On these units (as well as the orig EAR), adding a film bypass cap to the main PS filters really helps clean things up. Not a huge deal to do. Carefully drill an 1/8 inch hole next to the power supply caps to run one of the cap leads through.

Curious to do this mod, but not sure where the bypass cap is connected on the PCB? What value cap?

 

[mcgjohn]

Curious to do this mod, but not sure where the bypass cap is connected on the PCB? What value cap?

The toughest part is getting the volume control knob off. TAKE your time with it. Its a thin metal skin over a plastic knob that is pushed on to the pot shaft. I used Tea spoons with blue painters tape on the back of the spoons to prevent faceplate damage.
Once the knob is off, the rest disassembles pretty easily. For the power supply bypass cap, there is already an open solder point not used to reach the ground plane, so only one additional hole is needed to add PS bypass. I used a Jupiter 0.1uf. Today would have used a larger value with a 0.02uf bypass on the larger value. But the single .1uf really cleaned up the power supply. You can instantly hear it, the treble region is more open and natural sounding, not etched like the stock unit. I also replaced the coupling caps with Jensen copper foils. And replaced the 47K load resistors with Vishay bulk foils. If you don't want to spend the money on Vishay foils, you can use MILLs Wire wound 47K instead, just will require a little more work to fit them in. The MILLS are almost as quiet as the Vishays, but not quite. See attached Vishay PDF on audio noise.

 

[mcgjohn]

mcgjohn, I believe you have the doukmall 834 clone. I notice this unit has a volume control which is unusual for a phono preamp. Is this volume control useful? Can it be bypassed?

@pyoung272, since I am a crazed nut, I have both. The Doukmall and the EAR clone with the PCB fitted into an alum case. The circuits are the same, the case work is different. The board work on both is quite good. Parts quality is similar. Both used a toroid power transformer. If you like the looks of real EAR, then opt for the Doukmall version does a pretty good attempt at cloning the casework as well as the circuits. If you don't care about the case work, then you can save a few bucks and buy the other one from seller Along (something) has a bunch of numbers after "Along". If you opt for the Along version over the Doukmall version, be sure you get the version with the shielded toroid transformer. There are less expensive versions that have an open frame transformer. Take a pass on those. Here are a few pics. And if you really want to go nuts you can do the Yoshino mods to either unit. see attached PDF.

 

[pyoung272]

mcgjohn,

Thanks for the tip on which along unit to buy. I like the looks of the doukmall unit however the along version is much cheaper (about half of the price).
Can you tell me if the volume control on the doukmall version degrades the signal? I can see this volume control being useful as my current cartridge choice has a somewhat high signal (the volume control on my integrated amp is usually around the 8:30 position at my normal listening level) but would like to know if the the signal is degrade significantly by the addition of the volume control.

Patrick

 

[adnick]

Interesting topic, ordered a Douk board myself, it’s not here yet though.

Impressed with the build @StepheK did and that prompted my order. Figured I’d do a separate case for the power transformer but haven’t purchased a transformer yet. Have several in the parts bin that might work but thought I’d buy a new one for this endeavor.

Also thinking about populating the board with the tubes on the opposite side so they can protrude and be visible without showing the board, just an exercise in aesthetics’s


Don’t need another preamp, just couldn’t let y’all have all the fun.....


Andy

 

[patient_ot]

I have a Denon PMA 7.5 Integrated amp with a dedicated Phono stage. IT works well But I was wondering if I would get better performance for an external Phono Pre-amp say under $400.00??.

I would also like to connect two Turntables so I could switch back and forth???

My system is as follows:
-Denon PMA 7.5 Integrated amp
-Snell K Speakers
-Thorens TD-165 stock TP-11 arm [med-mass] w/ Nagaoka MP-110 cart & Ortofon OM-20
-Pioneer PL-518 w/ AT VM-95ML cart

....looking to maybe get a MC cart. in the future for more details sound??

Any suggestions!?

Steve,

In that price range I recommend you stay away from the off brand ebay clone crap that's likely loaded with counterfeit parts and a potential electrical safety hazard. Lots of fan boys here but groupthink exists on all forums it seems.

Go to Music Direct, Crutchfield, or whatever your reliable online audio dealer is (with a generous return policy), and find something that looks like it has the features you need in your price range. If you can afford to buy 2-3 units and home audition them, do that, and return whatever you don't like.

If you are planning to continue to use any AT MM cart, I would recommend limiting your choices to phono preamps with 100pf of input capacitance or less.

RE: the ability to hook up two turntables at once, not a likely feature in the $400 and under price range. Usually a feature like that only exists in higher priced stuff. Feel free to look if you want, but I wouldn't fixate on this requirement.

 

[Mr Boochie]

In mine, the low noise 7025 were clearly better than the 12AX7 tubes I tried.

RCA 7025 are such nice tubes. And they last forever!

 

[doctor fuse]

RCA 7025 are such nice tubes. And they last forever!

Someone sell me a gaggle of 7025s (for cheeep) ASAP!!!

 

[Mr Boochie]

I'm using these now. The resolution detail is pretty extraordinary. Nice tubes, as long as they don't mess up your RIAA EQ curve.

 

[doctor fuse]

In that price range I recommend you stay away from the off brand ebay clone crap that's likely loaded with counterfeit parts and a potential electrical safety hazard. Lots of fan boys here but groupthink exists on all forums it seems.

The most common "groupthink" on this forum is "USA good! China bad!". If that is more important to you than sound quality, then buy USA. But the sad reality is Chifi now offers better bang for the buck, than even USA-designed gear manufactured in China.

It should be noted that many forum residents here either make, flog, or formerly flogged hifi gear. You can take the man outta the salesman, but you can't take the salesman outta the man!

 

[patient_ot]

The most common "groupthink" on this forum is "USA good! China bad!". If that is more important to you than sound quality, then buy USA. But the sad reality is Chifi now offers better bang for the buck, than even USA-designed gear manufactured in China.

I have gear made in countries all over the world in my system, including China. The difference is there is no off brand crap, which lacks basic safety certifications. Some people don't understand the distinction, and throw around statements like you just did.

People also buy these things and have no idea what they are getting. In a previous thread about them, the purchaser didn't realize the SUTs inside the box were fake and wondered why there was a 9V battery inside.

Good luck getting any kind of warranty or dealer support if something goes wrong with one of these "clones".

 

[StepheK]

Also thinking about populating the board with the tubes on the opposite side so they can protrude and be visible without showing the board, just an exercise in aesthetics’s

I thought about that after I had assembled the board and was working out how to mount it lol. I'm OK with how it ended up with the tops of the tubes peaking out.