There is a lot of Tonepump Tonedump discusions over here, so I decided to bring some information from the source, since there's nearly no info on Spector's web.
I live in Czech Republic, where are Euro Spectors made and know, that preamp also comes from Cze.
It was designed for Spector and made by little company called Michalik. They sell this preamp here under name BP-4, and sell it to Spector under name Tonepump. I'll try to translate it's description, apologize my english. It could be called stupid marketing talk, but I think it is useful:
Well, I was little bit confused from that Boost/Cut EQ parameters, so I've asked directly mr. Michalik.
He told me that Tonepump is exactly the same circuit as BP-4. That eq is really cut/boost, not boost only, in spite of Spector says it is boost. It means, preamp is not flat at all when EQ is turned fully of! It is IMO very important fact. There's no middle dent on the pot, so it looks like on my old preEB MM Sabre,which was cut/boost too, with no pots dents.
I asked him for some wiring diagrams- I would like to rewire my Spector to Volume/Balance, too. He sent it to me and I translate them from czech to english. Again, hope it's translated correctly, I've just edited it in Photoshop
One pickup wiring
[Invalid or Expired Link Removed]
Two pickups with two volumes
[Invalid or Expired Link Removed]
Two pickups with volume and balance
[Invalid or Expired Link Removed]
Hope it clears some doubts about Tonepump and will be helpful for someone.
Cheers, David
I live in Czech Republic, where are Euro Spectors made and know, that preamp also comes from Cze.
It was designed for Spector and made by little company called Michalik. They sell this preamp here under name BP-4, and sell it to Spector under name Tonepump. I'll try to translate it's description, apologize my english. It could be called stupid marketing talk, but I think it is useful:
BP-4 preamp
Active circuit BP-4 was designed for American bass guitar manufacturer SPECTOR. It is used in all European models and some US models since 2003 under business name Tonepump.
Basic advantage of used wiring is, that it doesn't use operational amplifiers, like the most of other preamp manufacturers, but it uses special wiring with JFET transistor, which behaves very similar to valves.
Operational amplifiers, when they're overloaded- which is on beginning of nearly every tone, are saturated. When they're saturated, there is a short recovery time(about several milliseconds) and whole circuit doesn't work in this short time. The result is, that we lose signal- beginning of the tone, its attack. Valve(and this preamp) doesn't behave like this and when it's overloaded, it softly distorts second harmonical, which is octave, which doesn't matter to the sound. And the first signal after peak is immediately played.
Op-amplifiers based preamps often solve this problem using two 9V batteries. But the problem is not solved, it is just delayed and this peak could be problematic in signal chain in amplifiers, mixing consoles etc.
The result of JFETs using is, that instrument articulates (because there's no loss on the beginning of the tone). Instrument is cutting through very good in the mix in low volumes, too, and tone is clear in every EQ setting, in studio or live situations.
BP-4 specifications:
Uses 9V battery
Power consumption 1,2mA
Battery life app 420 h, up to 1000 h when using hq alkaline battery
Basic gain +12dB
Controls:
Bass: +14dB/-4dB @55Hz
Treble: +14dB/-12dB @6,5kHz
Volume
Balance
Invalid Link Removed
Well, I was little bit confused from that Boost/Cut EQ parameters, so I've asked directly mr. Michalik.
He told me that Tonepump is exactly the same circuit as BP-4. That eq is really cut/boost, not boost only, in spite of Spector says it is boost. It means, preamp is not flat at all when EQ is turned fully of! It is IMO very important fact. There's no middle dent on the pot, so it looks like on my old preEB MM Sabre,which was cut/boost too, with no pots dents.
I asked him for some wiring diagrams- I would like to rewire my Spector to Volume/Balance, too. He sent it to me and I translate them from czech to english. Again, hope it's translated correctly, I've just edited it in Photoshop
One pickup wiring
[Invalid or Expired Link Removed]
Two pickups with two volumes
[Invalid or Expired Link Removed]
Two pickups with volume and balance
[Invalid or Expired Link Removed]
Hope it clears some doubts about Tonepump and will be helpful for someone.
Cheers, David