Doge 6210 - another great headphone amp
Feb 3, 2007 at 1:59 PM Post #16 of 416
Headphone listening is different from speakers just like speakers are different from live - you have to learn to be content with a smaller soundstage in going from live music to recorded music played on speakers, and in going from speakers to headphones you reduce it to a really miniature soundstage.

You will have a tendency to turn the volume up to bring the music closer and larger to make it more like speakers. This will collapse or compress the fore and aft soundstage and increase the distortion.

You must discipline yourself to turn the volume down some, to put the music further away from you. Instruments in the back should not sound loud but soft. The distance from near and far instruments will increase - too much volume and this distance compresses.

You absolutely need a quiet environment - no noises in the background - to hear soft passages at lower volumes.

Volume can't be too low or the tones won't bloom.

With headphones you can get a natural timbre unadulterated by speaker-room phase distortions, and good focused imaging with instrument separation, but at the cost of: weight to the music, fullness to the tone, and a larger sound stage - that you can get with speakers.

You must live with these deficits and not try to capture them by turning the volume up since this will cause other problems. Headphones offer enough compensating virtures over speakers to make up for what you miss. I only use my headphone system when I want to engage in intensive and maximally concentrated listening.

So keep the volume down to the point of no disctortion and good fore and aft soundstaging. Adjusting the volume properly is critical to getting the best sound.

If you get noises or other problems in one of the two channels, change the tube from right to left - front (tall tubes) first in the Doge.

Does the noise switch sides?

If not, switch the sides of the back (short) tubes.

In this way you can tell which tube is bad - replace the suspected one and see if the problem goes away. Sometimes it is poor pin contact. If the tube is not tight in putting it in or out of the amp, you can bend the pins very slightly inward to get better pin contact. Sometimes this solves the problem.

The new Chinese tubes that come with the Doge need 5 hours of use to burn in and start sounding good. I have found the Chinese 6N14 (EL84 or 6BQ5 type) to be useful. Like any tube it needs to be properly mated to others or to the input electronics.

I rate tubes from 1 to 5 on richness.

1 is very lean in tone body but has sharp tone edges giving a highly detailed and sharp imaging sound with excellent instrument separation. This sound is very hard and can cause listening fatigue.

5 is very euphonic - a rich or fat tone body with poor edge definition so the tone spreads out in an overly liquid soundstage and the tones tend to blend together with poor instrument separation and poor muddy imaging.

For me, a rating of 3 to 3.2 is best but sometimes I prefer the slightly greater sharpness and focused images of down to a 2.5 and sometimes I prefer the slightly greater smoothness and rich timbre of up to a 3.4.

I am continuously updating my tube recommendations - check from time to time. I maybe have a thousand tubes and can provide all the tubes listed. Here are some good tube combos with the Doge - the many bad ones are not mentioned:

Use the two Chinese 6P14 in front with two GE 12AX7 (long plates of 17mm) in the back. Rated 2.9 on richness. Strong bass, detailed, but high resolution (need a good source).

Use two Russian 6P14P EB (or harder to find EP instead of the EB for slightly more power - good for the AKG K701) in front and two Electro Harmonix 12AX7 in back. Rated 3 on richness.

Use two Baldwin made in Japan 6BQ5 tubes in front with two GE 12AX7 long plates in back (or even two Electro Harmonix 12AX7) in back - neutral and uncolored, good for vocals and choral works. Rated 3 on richness. These Japanese 6BQ5 have one short rectangular slot in the middle of the plate and two long rectangular slots at the top and bottom. Other Japanese 6BQ5 tubes have one short rectangular slot in the middle of the plate and two short (not long like the Baldwin-Japan) rectangular slots at the top and bottom, and also sound good with the 12AX7 GE long plates. Rated 3 on richness.

Note: Many will prefer slightly more tone body richness (bloom) than the above and should use Use two Baldwin made in Japan 6BQ5 tubes in front with two Groove Tube (GT) 12AX7 long plates in back. This also adds slightly more deep bass (may be too much for the HD650) and gain (turn the volume knob down some). Rated 3.1 on richness.

Use two Russian 6P14P EB in front with two Groove Tube 12AX7 (11mm plate length) in back - one of the very best - I would go with this one if forced to use only one combo. You could "hot rod" this combo some by using the Russian 6P14P EP (instead of the EB) for slightly more power but I prefer the EB myself. Rated 3.1 on richness.

Use the two Chinese 6P14 (EL84 or 6BQ5 types) in front with two Mullard GB 12AX7 (medium plates - 14 mm) in back. Rated 3 on richness. Very slightly softer than above - more forgiving of the source.

Use the two Chinese 6P14 (EL84 or 6BQ5 types) in front with two Ken Rad 12AX7 in back. Rated 3.1 on richness. Even slightly softer than above - more forgiving of the source.

Use two GE 6BQ5 tubes in front with two Electro Harmonix 12AX7 in back. Rated 3 on richness.

Use two GE 6BQ5 tubes in front with two Sovtek 12AX7WA in back. Rated 3 on richness. Slightly more laid back than other combos. Rated 3.2 on richness.

Use two GE 6BQ5 tubes in front with two Telefunken smooth plate 12AX7 in back. Rated 3 on richness - slightly more forward (less laid back) than the above.

Use two GE 6BQ5 tubes in front with two RCA 7025 gray plates in back. Rated 3 on richness.

Use two GE 6BQ5 tubes in front with two Ken Rad 12AX7 in back. Rated 3.1 on richness.

Use two Amperex EL84/6BQ5 (I have halo getters but D getters may be even better) in front and two Electro Harmonix 12AX7 in back. Rated 3 on richness.

Use two RCA 6BQ5 in front and two Electro Harmonix 12AX7 in back. Rated 3.1 on richness.

Use two Russian 6P14P EB in front and two Telefunken 12AX7 smooth plates in back. Rated 3.1 on richness.

Use two Raytheon 6BQ5 made in Japan and two Ken Rad 12AX7 in back. Rated 3.2 on richness.

Use two Philips-Heerlen EL84 in front with two Electro Harmonix 12AX7 in back. Rated 3.2 on richness.

Use two Mullard-England EL84 (with D getters, not Halo getters) in front and two GE 12AX7 long plates (17mm) in back, to get a nice slightly sweet timbre - rated 3.2 on richness.

Use two Raytheon/Japan, Hitachi, or other brands of 6BQ5 made in Japan, in front, with two German RTF (short plates of 10mm) in back. Rated 3.2 on richness.

Use two Russian 6P14P EB (or harder to find EP instead of the EB) in front and two GE 12AX7 medium plates (13mm) in back. Rated 3.2 on richness.

Volume note: With two 12AX7 GE long plates and two Chinese 6P14, I turn volume knob up very little but if I switch the Chinese 6P14 for two Philips-Holland EL84 (that test strong as new), I have to turn the volume knob way up over the previous setting, and the richness changes to 3.2. Some combos do require turning the volume knob up more than usual. Most are not too different though.

Use the two Chinese 6P14 in front with two Sylvania 12AX7 in back. Rated 3.3 on richness.

Use two Sylvania 6BQ5 in front and two Electro Harmonix 12AX7 in back. Rated 3.3 on richness.

Use two Russian 6P14P EB in front and two RCA 12AX7 or 7025 gray medium (13mm) rib plates in back. Rated 3.3 on richness - a fun, rich and lush sound that some will like (I like it occasionally, along with the one above and below).

Use two Mullard (Halo getters, not D getters) in front and two Sylvania 12AX7 or 7025 with long (17mm) gray T plates and halo getters. Rated 3.35 on richness.

The match is the thing: The Russian 6P14P EB, or even the Chinese 6P14, as output tubes give great sound when matched to the right 12AX7. I never thought such great sound was possible from a Chinese tube but the Chinese 6P14 sounds great with the tubes such as the GE 12AX7 long (17mm) plates.
 
Feb 5, 2007 at 7:19 AM Post #17 of 416
since there are two headphone outputs, would it degrade the sound to use both of them? what if the headphones are different, such as an AKG K701 and a Panasonic headphone?
 
Feb 5, 2007 at 3:40 PM Post #19 of 416
Quote:

Originally Posted by cotdt /img/forum/go_quote.gif
since there are two headphone outputs, would it degrade the sound to use both of them? what if the headphones are different, such as an AKG K701 and a Panasonic headphone?


When using two headphones connected at a time the impedance is half of the total of the two connected HPs and the sound may become colored/distorted - two Grados would have a load of 16 ohms which could be a problem. Two HD650 would present aload of 150 ohms which is fine with the impedance selector at 60 ohms. Set the 3-way impedance switch to a setting closest, or even below, to the total HP load. If the impedance selector is too high of setting then tones may become bloated.

Best to use two of the same headphones (or at least two that match on sound DB output) together to avoid one HP being too loud and the other too quiet at the same volume setting.
 
Feb 5, 2007 at 4:41 PM Post #20 of 416
Quote:

Originally Posted by jmmtn4aj /img/forum/go_quote.gif
Wow, that does indeed look like a solid piece of work. I can't it on Cattylink though?


I ordered one from Cattylink a couple weeks ago. It's not listed on their website, but you can email them and ask for a quote on the 110V version.
 
Feb 9, 2007 at 6:31 AM Post #21 of 416
I got mine from Cattylink a few days ago. It is still burning in although it might not be necessary.

One of the screw came in loose within the case, so I opened the bottom cover to tighten up all the screws. Quite a few of them are not fully secured.

All point to point construction except the volume pot. The quality of the components are just so-so.

But it sounds quite good with all stock tubes.

I tried the crossfeed on/off, but i can't hear the difference with Senn600 or AKG701. Is it just me? I will check out the switch on weekend.
 
Feb 9, 2007 at 3:27 PM Post #22 of 416
I think you will find how the amp sounds, either good or better, after you experiment with different tubes with your heapdhones.
 
Feb 9, 2007 at 6:45 PM Post #23 of 416
That's good, that means there is plenty of improvement available with component upgrades. I like this amp because it uses transformer-coupled output which to me has always sounded better than capacitor-coupled output which the vast majority of tube amps use.
 
Feb 9, 2007 at 8:09 PM Post #24 of 416
Quote:

Originally Posted by pftrvlr /img/forum/go_quote.gif
I got mine from Cattylink a few days ago. It is still burning in although it might not be necessary.

One of the screw came in loose within the case, so I opened the bottom cover to tighten up all the screws. Quite a few of them are not fully secured.

All point to point construction except the volume pot. The quality of the components are just so-so.

But it sounds quite good with all stock tubes.

I tried the crossfeed on/off, but i can't hear the difference with Senn600 or AKG701. Is it just me? I will check out the switch on weekend.



Sounds bad with stock tubes.

Cossfeed differences depend much on the program material - some CDs have only a very subtle difference.

The crossfeed expands the tone body (enlarging the tones) but blurs tone body edges and increases liquidity, which destroys sharp tone imaging, instrument separation, and inner detail while reducing harshness of bad sources or ICs. This is generally a slight effect with the Doge though.
 
Feb 10, 2007 at 2:02 AM Post #25 of 416
Quote:

Originally Posted by pftrvlr /img/forum/go_quote.gif
I tried the crossfeed on/off, but i can't hear the difference with Senn600 or AKG701. Is it just me? I will check out the switch on weekend.


As I indicated before, the difference in crossfeed settings depends on the source material to a great extent.

I have done some experimenting and it is hard to detect any difference at times.

The Odeum (Greek for hall) setting, which should expand the soundstage in crossfeed, actually does the opposite. It offers sharper imaging and seems to be slightly quieter in volume to me. I turned the volume up slightly when it was on the Odeum setting, and compared it to General (which seems to use crossfeed but should not - Chinese translation problem?). Good tubes that image well are needed to compare. I did detect better imaging on the Odeum setting and a larger soundstage on the General setting. However, the amount of crossfeed used is small. I still prefer the better 3-D imaging on Odeum.

I sell 2 Electro Harmonix 12AX7 along with 2 new Russian military EL84 type tubes for $35 total shipped anywhere, to Doge owners. Then you can hear how bad the stock tubes are.
 
Feb 10, 2007 at 4:22 AM Post #26 of 416
drarthurwells, I've got two 12AX7EH, I will try them out tomorrow. What other tubes can you recommand?
 
Feb 10, 2007 at 7:44 AM Post #27 of 416
This is from my previous post (on the first page) where the EH12AX7 combos are in bold:

I rate tubes from 1 to 5 on richness.

1 is very lean in tone body but has sharp tone edges giving a highly detailed and sharp imaging sound with excellent instrument separation. This sound is very hard and can cause listening fatigue.

5 is very euphonic - a rich or fat tone body with poor edge definition so the tone spreads out in an overly liquid soundstage and the tones tend to blend together with poor instrument separation and poor muddy imaging.

For me, 3 is best but sometimes I prefer the slightly greater sharpness and focused images of down to a 2.5 and sometimes I prefer the slightly greater smoothness and rich timbre of up to a 3.75. Some might prefer a 2 while some others might like a 4.

Here are some good tube combos with the Doge - the many bad ones are not mentioned:

Use the two Chinese 6N14 (EL84 or 6BQ5 types) front with two Ken Rad 12AX7 in back. Rated 2.8 on richness.

Use the two Chinese 6N14 in front with two GE 12AX7 (medium plates of 14mm only) in the back. Rated 2.8 on richness.

Use the two Chinese 6N14 in front with two Sylvania 12AX7 in back. Rated 3.4 on richness.

Use two RCA 6BQ5 in front and two Electro Harmonix 12AX7 in front. Rated 3.1 on richness.

Use two Sylvania 6BQ5 in front and two Electro Harmonix 12AX7 in front. Rated 3.35 on richness.

Use two Amperex EL84/6BQ5 (I have halo getters but D getters may be even better)) in front and two Electro Harmonix 12AX7 in front. Rated 3 on richness.

Use the two Philips-Heerlen EL84 front with two Electro Harmonix 12AX7 in back. Rated 3.2 on richness.

Use two Russian 6P14P EB (or harder to find EP instead of the EB) and two Electro Harmonix 12AX7 in front. Rated 3 on richness.
 
Feb 15, 2007 at 1:37 AM Post #28 of 416
Tips for Doge 6210 owners:

Use the tall tubes (output) in front and short tubes (preamp or input) in back.

Always use the 60 ohm setting for impedance. With HD650 this may still be the best but try the 300 setting and test. Using two headphones reduces the load by the sum of the half of the impedance of each HP - using two HD650 is 150 ohm load since the HD650 is rated at 300 ohms.

I prefer the Odeum setting for sharper imaging - the General setting expands the soundstage but blurs images of individual instruments.

Never turn the amp on unless a source is connected and the HPs are connected. Turn off amp when disconnecting anything or reconnecting anything (except a second headphone).

The Doge has great low level resolution and you can clearly hear detail in soft passages. Listen in quiet environments and keep the volume down to maximize the fore and aft images of the soundstage.

The Doge is very responsive to different tube set ups - some sound terrible and some sound great. Select combos with care. It has great resolution of both detail and of nuances in tone body (timbre) - it will reveal the warts in your system.

If you are not getting absolutely great sound sound with the Doge 6210 then it is because of your tubes, or other parts of your system (or possibly some part defect in the amp).
 
Feb 15, 2007 at 5:30 AM Post #29 of 416
Quote:

Originally Posted by drarthurwells /img/forum/go_quote.gif
I prefer the Odeum setting for sharper imaging - the General setting expands the soundstage but blurs images of individual instruments.



I though the Odeum option turns the crossfeed on therefore blurs the images. I must be wrong? I haven't really be able to compare them by myself.
 

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