Harp Blaster and Impedance
Sun, 04/12/2026 - 07:53
Hi Greg,
I have a Hohner Harp Blaster (HB52) that I use either with a Laney Cub 10 amplifier or a Lone Wolf Alpha Wolf pedal. I run the Harp Blaster into an XLR cable and then into an XLR Female to 1/4" jack TS mono adapter. The manual says the Harp Blaster is high impedance, and the input impedance on the Laney amplifier is 1 MOhm. The Alpha Wolf says "they only require a 1/4" unbalanced High Z input or an impedance matching transformer". Should I be using a transformer with my Harp Blaster, such as the "Whirlwind Little IMP Impedance Matching Transformer" from your website, or am I fine without a transformer?
Thanks for your help,
Greg McGuire
Mon, 04/13/2026 - 07:43
#2
Thanks Greg for the quick
Thanks Greg for the quick reply. I'm glad to hear I got everything I need. Have a great day!
Hi, GregThe quick answer is no - you do not need an impedance matching transformer. Your mic is high impedance and your amp is high impedance.
The longer answer is a bit more involved. Everybody gets confused about this, so don't feel bad, but XLR connectors are used in two very different ways:
1. High Impedance (Rare) When used with high impedance mics like the Harp Blaster (which is exceedingly rare in today's world), they need a cable that is wired in unbalanced mode. That cable will have an XLR connector at one end and a quarter inch mono connector at the other.
These cables come in two flavors:
A. The Harp Blaster and most new devices want them wired "pin two hot".B. Older microphones (like Hohner's earlier Blues Blaster) required the cable to be wired "pin three hot".
2. Low Impedance (Standard) When used for low impedance mics (the worldwide standard), the cables are wired in balanced mode and have XLR connectors at both ends.
What's frustrating is that you can't tell what a microphone needs by looking at its connector. Because low impedance XLR is the worldwide standard, people who don't know are tempted to assume that any mic with an XLR connector is the same.
What's worse, it violates the rule we have all come to accept and love: that if you can connect it together, it must be right. In this case, however, the wrong cable can render you silent or give you poor performance.
To further confuse the issue, most of us have heard of a device called an impedance matching transformer, and one could easily assume that its only job is changing the impedance to match a microphone to an amplifier.
In fact, an impedance matching transformer provides two functions:1. The one its name implies (matching impedance)2. The conversion between balanced mode and unbalanced mode wiring
The cables physically connect the mic's signal to different pins on the XLR connector between these two modes.