[Pricklely Peete]

How much is this person asking for the pair ? Looks like 5 Star GE's unless I'm mistaken.
 
They should be half decent tubes provided the price is reasonable.
 
Peete.

 

[Skylab]

For sure they are real GE - you can tell by that "dot" pattern that is etched on the glass below the number.

 

[Nada]

Thanks for the advice about the GE 7025. I got them for USD27 and will compare them with another GE pair of equivalent value:
 

 

 

[SP Wild]

7025 vs 5751 - please let us know which of these tubes are better in terms of SQ and also gain, noise and hum.  Cheers.

 

[Nada]

I wonder which factory these came from?
 
http://i732.photobucket.com/albums/ww321/maliaros/tubes/IMG_4622.jpg
 

 

[Pricklely Peete]

Mesa Boogie label (Guitar Amps) "7025 STR's""  could be anything from Groove Tubes to EH, Sovtek or Ruby. Are they NOS Mesa tubes from the 80's or 90's ? They likely are nowhere near as good as the GE tubes you bought. Check out some Amperex orange or white label ECC83's along with Telefunken gray long plates (diamond bottom) if the budget allows. Seimens is another excellent ECC83. Steer clear of RFT unless they are tested and matched (with a DOA guarantee). The RFT's can be a bargain in a NOS ECC83 but they are also a little dark sounding and have QC issues (unless tested).
 
Peete.
 

 

[Nada]

Thanks for the info Peete about the Mesa tubes. They didn't look to well made judging by the photo so Im not surprised they aren't recommended. I will try and compare the GE 5751 and 7025 in the next couple of days.

 

[jdmoorman]

Does anyone know what the function of the 6HU6/EM87 tube is?
All references I have found talk about tuning functions - obviously irrelevant to this amp.

 

[SP Wild]

Doesn't seem to anything other than power the VU meter.  However changing it may change the sound, because it is in the circuit.

 

[burgunder]

Has anybody tried this amp with any of the newer high-end cans like HD800, T1 or LCD-2? And if so how was the sound.

 

[Skylab]

Unfortunately I had already sold mine - a pity, as it might be a good match with the LCD-2 specifically.  But I never tried it.

 

[moodyrn]

X2. Out of all the things I've sold, it's the one thing that I've regretted selling. There was just something special about that amp, IMO it competes well with tube amps far and beyond it price point. Now that I have the he-5s, I think it would be an excellent match for those with it being a transformer coupled amp. It does hum with low impedance, high sensitivity headphones. But with low impedance headphones with low sensitivity, and all high impedance headphones, it's truly magical. The speaker outs are rated at 5 watts, and I think you get those same 5 watts out of the headphone out.(not 100% sure though) I remember taking a look inside and could'nt find any resistors between the speaker outs and headphone outs.

 

[SP Wild]

Quote:

Has anybody tried this amp with any of the newer high-end cans like HD800, T1 or LCD-2? And if so how was the sound.

It has plenty of drive for the LCD2, T1 and HD800, I am using the K1000 with it and there is no changes between the speaker taps and the headphone jack.
 
But alas, ultra hi resolution cans like the ones mentioned is better paired with a higher resolution amp.  The MigDa works perfectly for yesterdays flagships, but todays flagships need more.  However for its price, perhaps we are asking a bit too much, for it is an excellent little amp.

 

[moodyrn]

Quote:

 I am using the K1000 with it and there is no changes between the speaker taps and the headphone jack.  

 
That supports my thinking that there is no resistor between the headphone out and the speaker out. It's easy to start comparing it to high end amps because it sounds so good(for it's price). But when it falls just short of their performance you have to remember that it's only 414.00. It's easily my recommendation for tube amps under 600.00.

 

[BmWr75]

Quote:

RE: difference between EL84 and EL84M for Ming Da. 
 
   Can the EL84M be used in place of the EL84 in the Ming Da MC84-CO7 ?
 
I asked the Ebay seller that question and this is his reply: " [size=10pt]Yes, but EL84M maintains more anode voltage than EL84." [/size]
 
[size=10pt]I have no idea at all if that is a no no or if its OK. [/size]

 
Any suggestions to share on that subject ?
 
[size=10pt]  [/size]

Both tubes will work fine in this amp.