Thomastik’s new Peter Infeld bass strings, unveiled at the 2025 ISB Conference in Tallahassee, are designed to bridge the tonal divide between Belcantos and Spirocores—offering the warmth, roundness, and bow response of Belcantos with the gritty growl and sustain that jazz players love in Spirocores. These high-grade hybrid strings cater to both orchestral and jazz musicians, delivering a balanced, versatile sound that adapts beautifully across genres. To help players find their perfect match, Thomastik has also released a sound chart—though individual instruments may color the tone slightly.
 
INTRODUCTORY PRICE: $569 inc. GST
*Strings not sold separately (at this stage)
 
Technical Details
Vibrating string length:  104.0 cm  |  40.9"
Usable from 103.0 cm/40.6" up to 110.0 cm/43.3"
Spiral rope core
Chrome/Tungsten wound
Thread colour - Tailpiece end:  Purple
Thread colour - Peg end:  Orange
 
String Tension:
G Sol I  -  28.8 kg  |  63.5 lb
D Re II  -  29.3 kg  |  64.6 lb
A1 La1 III  -  29.3 kg  |  64.6 lb
E1 Mi1 IV  -  30.5 kg  |  67.2 lb
 
Additional Single Strings available:
C1 Do1 IV  -  32.8 kg  |  72.3 lb
H2 Si2 V  -  30.7 kg  |  67.7 lb