[putente]

Quote:

Nice one..... Yes Ron is a great guy, very knowledgeable. I can't recall trying that combo, I will have to give it a try.

 
 
You definitelly should! I'm really impressed by this little amp's sound capabilites... 

 

[putente]

Btw, has anyone ever measure the output impedance of the P4, or does that depend on the opamp setup inside?
 

 

[dtdownunder]

I love sound and I am, as you also appear to be, with finding the best sound within my budget.
 
I habe recently upgraded my headphones from "Grado 325is" to the "Beyerdynamic T90" which I am very happy with. 
 
Today, I purchased the iBasso P4 portable amp which you have discussed in detail in this threat. I do enjoy the sound of that amp. It may be lacking a little bit on the lower end but the clarity is really good.
 
I have been following this threat for some time and today I decided to join this forum. 
 
I would also like to improve the sound by adding new chips as many have done here. SpudHarris seems to know a lot about this.
 
I have been a musician all my life but as far as this kind of audio equipment is concerned, I really do not know much. Not even sure what these chips actually are. I will continue reading up on it. In the meantime I have the following questions and I would really appreciate a reply.
 
the following has been recommended as worthwhile additions to the P4: LME49990, HA 5002 buffer, ISL5002. 
 
I have the following questions:
 

• are these the only components that I need to buy in order to upgrade? How many of each? (i learned that the ISL5002 is a dual chip and only one is needed. What about the other two? How many do I need?)
• Would anyone please very briefly explain what difference these components make and what they are? (just very briefly as I do not want to impose). I know a lot about sound but not that stuff
• Would I be able to install these chips by myself without risk of damaging anything? Is it difficult?
• Where can I buy the ISL5002 and the HA5002? (I am based in Australia).
• Do I need to look for a specific Brand or are these just generic descriptions and any will do?

 
[size=x-small]Sorry about all these questions. Just trying to get into this.[/size]

 

[dtdownunder]

Also
 
I found the LME4990 online in Australia. However is full title is "LME49990 MA" or "LME49990 NOB" - Is this what I need for the P4? What is the difference between "MA" and "NOB". Does it matter?
 
I also found the ISL5002 again described as ISL5002 21bz   -   Is this correct?

 

[dtdownunder]

made a mistake:
 
the LME49990 has either the ending "MA" or "NOPB"
 
Which one do I need to get for the P4? What is the difference. 

 

[Bugdozer]

I'm running an 8620 opa, 5002 buffers and BB 627s in the V/G channels driving my Etymotic ER-4S.  I've tried many combos but I always seem to come back to this set up.

 

[dtdownunder]

Thank you.
 
I have taken the advice from Ron (HiFlight) and decided to go with the set up that he recommended and which he kindly agreed to provide to me.
 
He appears to be very knowledgeable and gave me a lot of information. Very nice guy. I will update once I have the set up that he will post to me. We have been emailing back and forth and he addressed all my questions in detail. 
 
I will let you know once I have that set up installed. 

 

[dtdownunder]

Have u had a chance to listen to the Beyerdynamic T90? I am quiet impressed.

 

[Angular Mo]

Quote:

Well, after contacting Ron (HiFlight) about the ISL55002 chip, I finally got it up and running in my P4! He's really nice and supportive, and following his suggestion of using the ISL55002 in L/R with the AD797 chips as buffers and dummy ground chips, I achieved the kind of sound I was looking for from my P4, making it sound much like a tube amp, warm and musical, yet detailed with great bass performance! I'm very happy with this setup! 

I will have to try this config, thanks !

 

[Jackson9696]

Just found out from ibasso that the p4 is discontinued but the p5 will be out in a few months.

 

[CJG888]

Any information on the P5?

 

[Jackson9696]

No not yet, ibasso only told me that it would be released in a few months.

 

[CJG888]

This is where I bought all mine.....

LME49990

The ISL5002 are a little tricky to get as they come on a special adapter with resistors on the base. I bought mine from Ron Kerlin (HiFlight). He is my OpAmp Guru and an absolute gent, I'm sure he will sort you out if you drop him a line.

Hope the link above works, I've not done this on the iPad before.

Best of luck.

I've just ordered 2x single LME 49990 and 2x HA5002. How many ISL5002 do I need?

 

[SpudHarris]

It's a dual OpAmp so just 1 off is needed....

 

[Pete7]

Anyone tried AD744 OBCA? Wondering if I could try this with BUF634's without frying the unit. This combo used to sound incredible in the Larocco PR II.