Difference between Slam and Normal Singlepower Tubeamps
May 8, 2006 at 8:14 AM Thread Starter Post #1 of 4


Headphoneus Supremus
Sep 22, 2005
I'm currently looking at the
PPX3-6SN7 $749 with Solen Stage I
MPX3 $949
Slam PPX3-6SN7 $899
MPX3-Slam $1149 with NOS tubes.

Apparently, the Slam versions are more powerful. Why is this? Do they use different tubes for gain and output?
I heard somewhere that the Slam can use 5687 tubes. What are these?

I'm planning to use HD650 and K701. Are the normal amps good enough?

May 8, 2006 at 12:44 PM Post #2 of 4


Headphoneus Supremus
Dec 31, 2004
The SLAM amps use the 5687 tubes as outputs whereas the "normal" amps use the 6sn7 as outputs, the driver is the same (6sn7). Using powerful tubes like the 5687s satisfy the needs of low impedence headphones and low efficeincy headphones like the 701, given that they require alot more current than a high impedence headphone like the 650.

Given that you're getting the 701s, I'd go for the SLAM amp for sure.


May 8, 2006 at 4:27 PM Post #4 of 4


Headphoneus Supremus
Aug 15, 2003
The "SLAM" version of the PPX3, come standard with the 6CG7 input tube, and two 5687 output tubes. It includes the Solen I upgrade. It also has a "texture" control on the front panel. Some feel that the "texture" control is of little benefit, I disagree on that point.

For an additional $50.00, you can get the "SLAM" version of the PPX3, upgraded to the 6SN7 input tube. Everything else is identical to what is listed above.

(Of course other options are available to the models listed above, if desired.)

The regular stock model of the PPX3 comes in two varieties:

The least expensive is the one with all three tubes being 6CG7's. The more expensive one has all three tubes being 6SN7's. Neither of these units have the Solen I upgrade, or the "texture" control, included in the stock versions. (Once again you can have additional upgrade featured added as desired.)

If you were to get either of the regular stock models, you could use the same 5687 out put tubes that the "SLAM" does, by buying (2) adapters, but these are on the expensive side. So if you want the 5687 output tubes, then you should probably buy a "SLAM" version to begin with.

The 5687 output tubes have more power that the 6SN7, or 6CG7, as output tubes. The 6CG7 tube is the most economical of the three tubes, but offers less choices for tube rolling. The 6SN7 tube has many more tube rolling choices, but can become expensive, depending upon which tubes you want to buy.

Hope this helps!

- augustwest

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