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iBasso P2 - Page 6

post #76 of 324
Quote:
Originally Posted by jamato8 View Post
Well I went and did it.

I bypassed the large 4700uf power supply caps with .47 HiQ Black Gates and replaced the two 22uf polar caps with two 47uf HiQ and two .47 HiQ nonpolar Black Gates. The sound? Well they need some time but there is a bit of refinement. I am still running the stock opamps.
Sorry for my noob question again

According to the pic above, I see the 2 4700uf caps and another 2 small,standing caps (still dunno what are they?). But if I not mistaken, I see you replace six (sorry for my noob) caps? So, please help me clarify this and I would appreciate for some real pic
post #77 of 324
I replaced the two smaller caps (standing) at the bottom center of the image with 47uf caps and bypassed those and the two large 4700uf caps with .47uf HiQ Black Gates. The .47 are small enough that I placed them under the board as there is enough clearance between the bottom the board and the case. You also want bypass caps to have as short of leads as possible and this gets everything very short.
post #78 of 324
Quote:
Originally Posted by jamato8 View Post
I replaced the two smaller caps (standing) at the bottom center of the image with 47uf caps and bypassed those and the two large 4700uf caps with .47uf HiQ Black Gates. The .47 are small enough that I placed them under the board as there is enough clearance between the bottom the board and the case. You also want bypass caps to have as short of leads as possible and this gets everything very short.
Thanks jamato, that's really helpful?
I've just taken some googles and found out some 47uf and .47uf with different voltages. I wonder what the voltages of the BGs you use?
Here are 2 sites I found. If possible, could you please show me which I should get?
Prislister - Black Gate Capacitor Price List
Angela Instruments: Black Gate
post #79 of 324
I use Parts Connection in Canada. They ship fast, have the best prices and a very good selection. Because of the voltage I use the 6.3 voltage caps. So I use the .47uf HiQ Black Gate 50v (they only come in 50v) and the 47uf HiQ 6.3 volt. Black Gates are no longer made and there is NOTHING like BG's. They do take some time to form (break-in) but they are superb. I would order extras just to have them on hand but always check the working voltage of what you are changing caps in to make sure you have the right voltage cap. With electrolytics I get ones close to the operating voltage as I think they sound better but with film caps I go for much higher voltages. In a tube amp that might have 150 volts on a decoupling cap I would use a 600 volt film cap, as an example. Also the solder in the P2 as with the D1 is hard solder so you need to get a feel for it. I use a copper wick to pull the solder off of the pcp to open up the hole the cap is in. The circuit goes through the hole and if you drill out the hole with a tiny drill you can also take out part of the through the hole circuit.


http://www.partsconnexion.com/catalo...ctrolytic.html
post #80 of 324
Quote:
Originally Posted by jamato8 View Post
I use Parts Connection in Canada. They ship fast, have the best prices and a very good selection. Because of the voltage I use the 6.3 voltage caps. So I use the .47uf HiQ Black Gate 50v (they only come in 50v) and the 47uf HiQ 6.3 volt. Black Gates are no longer made and there is NOTHING like BG's. They do take some time to form (break-in) but they are superb. I would order extras just to have them on hand but always check the working voltage of what you are changing caps in to make sure you have the right voltage cap. With electrolytics I get ones close to the operating voltage as I think they sound better but with film caps I go for much higher voltages. In a tube amp that might have 150 volts on a decoupling cap I would use a 600 volt film cap, as an example. Also the solder in the P2 as with the D1 is hard solder so you need to get a feel for it. I use a copper wick to pull the solder off of the pcp to open up the hole the cap is in. The circuit goes through the hole and if you drill out the hole with a tiny drill you can also take out part of the through the hole circuit.


http://www.partsconnexion.com/catalo...ctrolytic.html
Thanks so much,jamato Now grasp it
With those BGs in the P2, I think the break-in time is by no way under 300-400h
post #81 of 324
Thread Starter 
Quote:
Originally Posted by Lil' Knight View Post
HiFlight, can you post the pic of your P2 after replacing the BG ?
The pictures on page 2 and the last page show the BG caps. They are the 2 closest to the edge, one has a bright reflection on top from my flash.

After much comparison and evaluation of sound, image and overall performance, I would recommend the AD746 in LR and LT6234 in IC2.

The OPA2107, while sounding good for the most part, tended to clip at higher volume settings with inefficient phones. The ADA 4841-2 and LT6234 lacked vocal presence. The 746 seems to do everything well.

The P2 tends to show differences between LR opamps more definitively than does the D1 or many other amps that I have used.
post #82 of 324
My P2 is on it's way,can't wait!I hope it sounds better then the C&C Xo. tracking number dosen't work yet.LOL
post #83 of 324
Ron How do you compare P2 with Xin Reference?
post #84 of 324
Thread Starter 

P2 vs Reference

Quote:
Originally Posted by kaushama View Post
Ron How do you compare P2 with Xin Reference?

I have been delaying a comparison between my Reference and P2 for several reasons:

The Reference takes a lot of time to really develop the sound that is the "real" Reference.

The P2 is really many different amps in one, as the sound changes more with a change of opamp than most of the other amps that I have been working with, including the D1.

My P2 only has about 30 hours of listening, so I wanted to let it develop a little further as well, although it doesn't really seem to change as much as the Reference.

I have also been trying a lot of different opamps in the P2. iBasso is quite interested in the results of many of these swaps, so I have spend a good bit of time corresponding with them.

I had narrowed the list down to some opamps that seemed to be very good.. the AD8620, OPA2107, LTC8241HV among others. While all sounded good, invariably I found certain conditions where the SQ suffered. Many times this was manifested as clipping under demanding input signals while using inefficient phone, such as my HD650s or PK1s.

I finally ended up using the THS4032. This is a great opamp, but because of the very high slew rate, it can cause instability in some circuits. Fortunately, the D1 and P2 are very stable, and this opamp has proven to work very well in both amps. I have not found any conditions that result in undesirable output characteristics regardless of phones.

So after settling on the 4032 as a final (?) configuration for my P2, I decided to spend some time comparing the P2 and Reference and trying to determine the strengths and weaknesses (if any) of each amp.

I fed both amps with high bitrate MP3 recordings from the line out of my iRiver H140. I also compared both amps with very efficient circumaural phones (Sony F1) as well as inefficient circumaural (HD650) and rather inefficient buds. (Yuin PK1)

Most of the recordings were instrumental and vocal, both male and female.

Here are my impressions as of now:

To match volume settings, it was necessary to set the P2 to the highest gain setting. As the Reference lacks any tone control, I kept the bass gain set to 0 on the P2.

Both amps sounded more alike than different. Both handled complex inputs and provided all the volume I could want or stand, regardless of which phones I used.

Both amps easily rendered the lowest bass that was present in the recordings accurately and with lifelike impact. Highs were detailed and airy in both amps, with the P2 sounding somewhat recessed, but not lacking, in the ability to render high frequencies. Overall, the P2 presented a warmer sound that seemed to be further back from the listener.

In contrast, the Reference soundstage was closer with vocalists being located right in front of the listener and exhibited a bit more presence.

The Reference is more revealing of shortcomings of source inputs than is the P2.

I would equate the Reference sound to that of the Etymotic house sound. Quite detailed and analytical whereas the P2 sounded more like the typical Sennheiser sound warmer and fuller.

I would suggest that from strictly a compatibility point of view, the Reference would work very well with darker phones such as Sennheiser and the iBasso would match up very well with brighter phones such as AKG, etc.

I hate to disappoint those who have made it this far in the review by not stating a clear winner, but in truth, they are both fine portable amps that deliver superb sound.

Some of the pros and cons of each:

IBasso P2:

Pros:
Ability to roll opamps. Ability to recharge batteries.
User selectable Gain and Bass settings, both of which work very well.
Very modest cost.
Superb build and finishing.
Outstanding customer support.

Cons:
It is a very long way to China should service be required.
Needs a charger about every 15-20 hours.
Lithium batteries not user replaceable.


Xin Reference:
Pros:

Superb overall performance regardless of what type of phones are used.
Resale value VERY high.
Very long battery life...hundreds of hours.
Able to order with 1/4" or 1/8" input and/or phone jacks or one of each if desired.

Cons:

Long wait for delivery, customer service can be sporadic, depending on Dr Xins work mode.
No onboard recharging. No user controls other than volume.

In terms of flexibility and performance vs cost, the P2 probably is the winner.

In terms of long battery life and just plug in and listen, without any need for technical expertise, the Reference comes out on top.

In the very important area of sound quality, width and depth of soundstage, and that all-important but intangible sense of realism, both amps fare very well and the choice between them would be strictly based upon ones personal listening preferences.
post #85 of 324
Thread Starter 
Yes, the LT1364 does sound quite good. That is what my P2 came with. I do like the THS4032 better than any of the other opamps at this point. It seems to do everything well. I just felt that the sound was fuller and more lifelike with the 4032.

I could never use this opamp in my Xin amps due to instability, but no such problem was present in either of my iBasso amps.
post #86 of 324
Thread Starter 
Quote:
Originally Posted by Shopper View Post
Seems like I must try the THS4032 (or THS4031 x2). I have them, I just lack the Browndogs.

Have you measured the DC offset, btw? Perhaps it might create issues, due to the 3 uA Ib of this chip.

I liked the THS4051 used as a buffer (so no offset problems).
So far in the iBasso, I have had no issues at all with the 4032, but have not measured and of the incircuit parameters. Perhaps the reason I was never able to get it to work satisfactorily in my Xin amps was due to the DC offset, although that small amount should not cause a problem.

The DC offset voltage is not a great deal different than that of many other popular audio chips, so I would expect no problems in that respect.

Most of the previous problems I have had with this opamp were due to the very high slew rate. It tended to oscillate in the signal circuit. I think that was more an amp issue than an opamp issue though.

The LMH6643 and ADA4841-2 are also very fast amps and works well in buffer, DAC and LR sockets in the D1 and have also worked without issue in the P2.
post #87 of 324
Thread Starter 
Quote:
Originally Posted by Shopper View Post
The LT1364 has 1000V/us but seems very stable. A big advantage, together with the lowish 600nA Ib (for this type of opamp). The LT1361, although a little slower, is very good as well.

The LMH6643 (actually LMH6642) I didn't like too much, too sterile, I preferred the LMH6654 (dual version is LMH6655) which was more defined and much more musical to me, and had a little fuller sound. You might try two LMH6655 in the D1 buffer positions.
Shopper...

Thanks for the info on the LMH6655! I haven't tried that one but it sounds like it should be a fine buffer. I will get some and try them in a couple of my other amps. I have not yet found a buffer I really like in the D1. My best performance is by running the dual AD797s or the THS4032 with buffer sockets bypassed. Maybe the 6655 will be just the ticket.

BTW, the THS4032 is far and away the best performer I have found so far for the P2. They seem to be made for one another.
post #88 of 324
Ron, what is a good source for the THS4032?
post #89 of 324
Nice comparison Ron!
post #90 of 324
Hi,

How do you compare P2 and Hornet amp? I just want to know initial impression coz I have ordered both amps.

Thanks,
Jon
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