I am very pleased to announce modifications to VTV amplifiiers using the Purifi amp modules. I can also mod other brands of amps that also use the Purifi modules like Nord and Apollon (call for details). The VTV amps are the least expensive way to get into the Purifi modules and they have a 30 day money back gaurantee on the stock unit and offer free shipping.
VTV has various versions of Purifi based amps they can sell you. I do mods to the Eval-1 stereo amp ($1089) and to the stereo, dual mono stereo and mono block amps that use the discrete input boards ($1500-$2200).
5-7-2024: The Purifi modules are so reliable I am now offering a two year warrantee on Purifi based mods. Obviously, if you abuse the amp or mod it in any other way the warrantee is void.
3-22-2022 : VTV is now selling Purifi based amps using the new higher current 1ET7040SA module.....more current and even better sound. Stereo amps start from $1799. Prices listed are the stock amps from VTV including shipping. We can mod all the solid state Purifi amps from VTV.
Here is a link to a review on my modified Eval-1 based Purifi VTV amp:
The latest version of this mod is better than the reviewed unit. I have removed a couple of parts for better sound and the WBT output jacks sound better than the older binding post bypass system. VTV has so many choices of amp that it might be confusing. The amp in the review and the one you would want to order from VTV is this one:
There are 5 different mods available. You can do as little or as many as you like.
Mod 1.....Purifying up the AC input and switching power supply I remove the stock steel shielded inlet/switch/AC filter combo and install a Cryoed and demagnitized Furutech AC inlet. There is already a good AC filter built into the power supply so this cheap filter is just adding distortion. I elminate the power switch as these mess up the sound and the amp draws so little current that it is best to leave it on all the time. This great sounding AC inlet is wired with Cryoed 14 gauge OFC wire insulated with foamed Teflon directly to the power supply and these wires are hardwired to the power supply (no connector). I do two other proprietary mods to the main power supply. The cost of this mod is $150.....$275 for mono blocks
Mod 2.....Mods to the output filter on the Purifi module. All class D amps need a filter on the output to filter the switching frequency. However, the purity of these parts is critical to the sound. I modifiy all 6 filter caps per channel and put them in the correct direction (the outside foil facing ground). This mod is very time consuming as I have to remove both boards and remove the heatsinks....then do tweaky mods and reassemble them. This makes a serious improvement. The cost of this mod is $150.
Mod 3.....WBT output connectors and better output wire. I install the WBT 0703Cu binding posts and change the wire to 14 gauge OFC cryoed copper in Teflon Foam insulation. I solder the wired directly to the ciruit board and jacks (do not use push on connecors). By the way, the best connector for you speaker wire is tinned bare ends.....then spades, then bananas......If you removed the connectors on both ends of your speaker wire you would be amazed at how much better your speaker wire is. The list price on two pairs of these WBT jacks is $180. The cost of this mod is $175 for amps that already have the stock binding posts and $200 for an amp that does not. If you already have the WBT 0703 jacks installed then the wiring mod is $50 .
Mod 4.....Raise the input impedance This mod is for the Eval-1 input board amp only . The Eval-1 board has an input impedance of 5K per phase. This is way to low for passive preamps and tube preamps...and higher impedance just plain sounds better. We raise the input impedance to 100K per phase. (Side note: The discrete op amp input board versions of the V TV amps already come with 50K input impedance and as part of our advanced mods package becomes 150K). The cost of this mod is $50.
Mod 5.....Advanced mods for amps using discrete input stages This includes the following:
A. Clean up the input wiring. I install my own custom wire on the input and solder these wires directly to the input board....right next to the input amplifier. I eliminate the input connector on the circuit board.
B.
Change all the input stage resistors and capacitors to better sounding parts
. Clean
up the power to the discrete input stages. The standard regulator on the discrete input stage buffer is the Sparko Labs regulators....these are very good parts. However, I modifiy them in two ways to make them sound even better. Then I replace the output caps on the regulator to my fav damped electrolytic caps and modified 1 uf Wima bypass caps. These caps are modified by me and marked for outside foil and installed so the outside foil is oriented to the lowest potential. I also mod the Sparko Labs 2590 op amp for better sound if you have those installed.
The cost of Mod 5 is $200.
The costs for the all out mod for an Eval-1 buffer input amp would be $550 (Mods 1-4 above). This is the cost of the mod by itself.
If you do not own an amp then the Eval 1 amp (commonly called Eigentakt) can be purchased from VTV for $999 including shipping to here.
Your
total cost (amp plus mod) would be $999 plus $550 = $1549 plus return shipping
The all out mod for a discrete input buffer amp would be $675 (Mods 1-3 and 5 above) for a stereo amp using the new higher current amp modules or the standard modules.
These prices are for a stereo amp. Discrete buffer mono blocks would be $775 and dual mono stereo amps would be $750.
Your total cost for the discrete input stereo amp with 2590 Sparkos installed plus mod would be $1648 plus $675 = $2323
Your total cost for the high current stereo amp plus mod would be $1831 plus $675 = $2506
Dual mono high current amp would be $2131 plus $750 = $2881
If you do not own an amp........it makes sense to get the latest better sounding higher powered version.
The gain is 27db, 200 watts into 8, 400 into 4 and 450 into 2 ohms. VERY low output impedance (high damping factor).
Mono amps or a dual mono stereo amp will always sound slightly better than a stereo amp using a single power supply.
You can have the unmodified VTV amps sent directly here and only have one shipping fee since they ship for free. Of course, you can buy the VTV amps and use them stock for awhile and send them in for a mod later on. You can also send us Nord amps using the Purifi modules here to be modded, as well. Right now, VTV and Nord are the only companies making an input board for the Purifi modules that can accept both mono Pro discrete op amps and 8 pin dual dip opamps....giving the most versatility (so I recommend these brands above all others). As stated above, VTV is the cheapest, most versatile, free shipping, located in the US and 30 day return policy (on the stock unit.....not the modded unit).
Please call for more info.
I can do other custom mods....since this is all custom....he he.
For instance, I can change the input jacks to Furutech for slightly better sound (if not already installed).
We will have more information soon including pictures of a modified amplifier. We will also be having a tour of a modded unit so people can hear what the latest low distortion Class D modules can sound like when tweaked like crazy. Stay Tuned.
