[jboehle]

I would appreciate some comments on a PPA/Grado SR-225 combo. I have the Grado's on the way, but don't want to dismiss them without hearing them with a good amp first, as from everything I've read, they need loads of current. I have a PPA sitting around that I don't use currently, just wondering how it compares to the Grado RA-1 when paired with Grado cans. My PPA uses 4 buffers per channel and OPA637/OPA627 op-amps. But I could change to any op-amps one thought matched well with the Grados.

On another note, I have AT A900s on the way as well. The general opinion around here is that the A900s don't improve very much with an amp, but just wondering if anyone has tried a PPA w/ A900s?

-Jason

 

[Wodgy]

The PPA is a good, solid amp for Grados. There is no magic "synergy" with this particular combo, so you may find it too hard or harsh or bright, but it is a good, competent combo. The RA-1 has virtually no low bass and is certainly not competitive with the PPA in that area, but the highs of the RA-1 are a bit smoother; however the highs are also kind of grainy. In my opinion the RA-1 is mostly a joke (I used to own it, as well as the SR-125 and SR-225) but others will disagree and suggest that there is a huge amount of synergy here. Your mileage will vary. In my opinion, Pete Millett's hybrid tube amp has much more synergy with Grados (strong bass, smooth highs). People have said good things about the MAD Ear+ as well, but I haven't heard it.

 

[xtreme4099]

you can get synergy with the ppa with the right configuration, the right opamps and caps, sr225 sounds great, for people people to say that it sounds this and that way all the time is silly, there is no one ppa, since its a DIY project, what wodgy mentioned might be true of the stock ppa, 5002 buffers with the most basic of componentsl

 

[jboehle]

Well, here's the particular PPA I'm talking about:
http://www5.head-fi.org/forums/showthread.php?t=67566

Except now it has bass boost, class A biasing, and crossfeed added. I'm using the standard Elpac power supply.

Any suggestions on mods to my PPA to make it more Grado friendly? I figure I will have to fool with the gain a little, no big deal there.

-Jason

 

[MisterX]

Keep the gain low and don't be afraid to increase the value of R1.... You are going to have to experiment to find the best combination for your listening level.

BTW, some of us missed you in your absence

 

[sbulack]

The OPA637/627 are a good opamp match on the PPA with the Grado SR225. I happen to like the SR225 sound very much, and I thought that the PPA improved the sound I was getting from the SR225 sufficiently to make it worth the $400-ish I paid for the PPA. It's a good combination to my ear.

 

[xtreme4099]

LT1122 and LT1028 are even better, www.linear-tech.com, im currently using the 1028 in mine.

 

[HiGHFLYiN9]

Quote:

Originally Posted by sbulack The OPA637/627 are a good opamp match on the PPA with the Grado SR225. I happen to like the SR225 sound very much, and I thought that the PPA improved the sound I was getting from the SR225 sufficiently to make it worth the $400-ish I paid for the PPA. It's a good combination to my ear.

I run the same combo, the Grados sound fantastic on it.