Appreciate help with Polytone Mini-Brute Amp

**inlandbott** · 04-25-2022, 09:22 PM

Hi, All!

I recently picked up a Polytone Mini-Brute at my local Goodwill. I've done my Internet due diligence, but would appreciate any confirmations on my guesses to the amp's age, etc.. (see attached pics) I am thinking it is a 1977 model based on the speaker code, power transitor codes and hand written markings on the pre-amp chassis. I think that's right, but would like some confirmation. Polytone info is a bit scarce online

Thanks in advance!

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**Tal_175** · 04-26-2022, 06:05 AM

Goodwill, wow, good find. Very clean amp. You find Polytones in this condition listed for up to 700-800 USD on Reverb.
I have a very similar but 70's model with a fuzzy cover. I thought the polytones had fuzzy and diamond tolex in the 70's and early 80's. Based on that, yours might be a mid to late 80's model (unless the tolex was replaced?).

Mine also has the exact same panel as yours (no red knob, no reverb and with the slider), except it says "Mini Brute", not "Mini Brute I". So I think mine is an older model before the non-reverb models were called "Mini Brute I".

**RobbieAG** · 04-26-2022, 10:04 AM

I had a similar one back in the 80s and used it on a lot of gigs. It was great because it was so small and light and had a big sound. I had it repaired once, then it went out again and I gave it to a friend. Mine wasn't vinyl like yours - it was a black fuzzy material IIRC.

**inlandbott** · 04-26-2022, 11:31 AM

Originally Posted by Tal_175

Goodwill, wow, good find. Very clean amp. You find Polytones in this condition listed for up to 700-800 USD on Reverb.
I have a very similar but 70's model with a fuzzy cover. I thought the polytones had fuzzy and diamond tolex in the 70's and early 80's. Based on that, yours might be a mid to late 80's model (unless the tolex was replaced?).

Mine also has the exact same panel as yours (no red knob, no reverb and with the slider), except it says "Mini Brute", not "Mini Brute I". So I think mine is an older model before the non-reverb models called "Mini Brute I".

Thanks for the reply! Yeah, I was surprised on how clean it was. It was still $140 even at goodwill. They've jacked their prices a lot in the past couple of years

The only reason I don't think mid to late 80s is because all the dates codes I've found say '77. Even with the Internet, info is scarce. Can't image trying to sleuth this without it!

cheers!

**inlandbott** · 04-26-2022, 11:35 AM

Originally Posted by RobbieAG

I had a similar one back in the 80s and used it on a lot of gigs. It was great because it was so small and light and had a big sound. I had it repaired once, then it went out again and I gave it to a friend. Mine wasn't vinyl like yours - it was a black fuzzy material IIRC.

Hi, Robbie

They are neat little amps. Mine does have some electrical issues I need to sort out, however. Output volume is super low and the amp only draws about 8 watts! Need to get in there and start testing.

cheers!

**Tal_175** · 04-26-2022, 11:44 AM

Originally Posted by inlandbott

Hi, Robbie

They are neat little amps. Mine does have some electrical issues I need to sort out, however. Output volume is super low and the amp only draws about 8 watts! Need to get in there and start testing.

cheers!

Mine had the same issue when I got it. The issue was a caput pre-amp capacitor. It was more in the interface between the pre and power amps.

You can test if the issue is in the preamp if you have another amp with an fx loop. If you connect the preamp out of the Polytone to the power amp (FX receive) of the other amp, and if the problem is with the preamp, you'll experience the same issue. If the amp is loud with an external power amp (ie it gets as loud as you'd expect with that power amp) then the issue is in the power amp.

**inlandbott** · 04-26-2022, 11:54 AM

Originally Posted by Tal_175

Mine had the same issue when I got it. The issue was a caput pre-amp capacitor. It was more in the interface between the pre and power amps.

You can test if the issue is in the preamp if you have another amp with an fx loop. If you connect the preamp out of the Polytone to the power amp (FX receive) of the other amp, and if the problem is with the preamp, you'll experience the same issue. If the amp is loud with an external power amp (ie it gets as loud as you'd expect with that power amp) then the issue is in the power amp.

Ahh. Excellent! Thanks, Tal! That at least gives me somewhere to start and would be much better to have a bad cap than a bad power transformer! Much appreciated! I'll be sure to reply back after I get to it.

thanks again!

**Tal_175** · 04-26-2022, 11:58 AM

Originally Posted by inlandbott

Ahh. Excellent! Thanks, Tal! That at least gives me somewhere to start and would be much better to have a bad cap than a bad power transformer! Much appreciated! I'll be sure to reply back after I get to it.

thanks again!

Be sure to keep the volume low on the guitar or on the Polytone preamp when you connect to an external power amp. In the end, I had my tech fix the amp. I did this test to determine if it was the preamp. Once I found out that it was the preamp, I tried to wiggle the preamp circuit board with a pencil to see if it was a bad solder or connection issue that I could fix. It wasn't so I brought the amp to my tech.

**inlandbott** · 04-26-2022, 12:08 PM

Originally Posted by Tal_175

Be sure to keep the volume low on the guitar or on the Polytone preamp when you connect to an external power amp. In the end, I had my tech fix the amp. I did this test to determine if it was the preamp. Once I found out that it was the preamp, I tried to wiggle the preamp circuit board with a pencil to see if it was a bad solder or connection issue that I could fix. It wasn't so I brought the amp to my tech.

lol. yes, always good to keep that volume low!

thanks again!

**mad dog** · 04-26-2022, 02:31 PM

Looks like mid 80s. (I'm no expert, but owned a couple of that vintage.)

**inlandbott** · 04-26-2022, 03:40 PM

Originally Posted by mad dog

Looks like mid 80s. (I'm no expert, but owned a couple of that vintage.)

Cool. this is a long shot, but do you happen to remember the serial on any of your 80s polytones? Mine is P1828 and the speaker, chassis and power transistor date codes are all 77 or 78

thnx!

**mad dog** · 04-26-2022, 06:29 PM

Originally Posted by inlandbott

Cool. this is a long shot, but do you happen to remember the serial on any of your 80s polytones? Mine is P1828 and the speaker, chassis and power transistor date codes are all 77 or 78

thnx!

Found pics of the MB II. Serial no. looks to be PL 22699.

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Also had a MB IV. Didn't open up either one, so no idea on date codes.

**inlandbott** · 04-26-2022, 06:38 PM

Originally Posted by mad dog

Sorry to report, I never noted the serial numbers of either amp, a MB II and a MB IV. Didn't open up either one, so no idea on date codes.

lol. no worries. thanks for replying. II and IV would most certainly be 80s

**mad dog** · 04-26-2022, 07:46 PM

I edited my post, did find a serial number for the MBII.

**starjasmine** · 04-27-2022, 12:15 AM

Originally Posted by inlandbott

It was still $140 even at goodwill. They've jacked their prices a lot in the past couple of years

Nice find! Even if you put a couple hundred into repair, still quite a deal. Enjoy!

**inlandbott** · 04-27-2022, 05:53 PM

Originally Posted by mad dog

I edited my post, did find a serial number for the MBII.

Nice! Thanks. definitely got that 80s red knob and font

**inlandbott** · 04-27-2022, 06:11 PM

Originally Posted by starjasmine

Nice find! Even if you put a couple hundred into repair, still quite a deal. Enjoy!

Thanks!

**No_Jazz_Guitarist** · 09-12-2022, 10:09 AM

Referring to the Mini Brute I at the top:

Mine is identical but says just Mini Brute on the top panel.

Funny that the serial no. on mine is higher: P- 2421

**Greentone** · 09-12-2022, 12:06 PM

It' a mid-70s Mini Brute I. I have one just like it, one with the fuzzy covering, and one just like Mad Dog's.

**Doncharnin** · 04-21-2023, 04:38 PM

I have owned a Mini brute for many years. I am an original owner. the serial number is 5307 I would love to know the age and fair price for it.
I am interested in selling it.
Thank you

Don

**inlandbott** · 07-10-2023, 01:23 AM

Hi, don

awesome! Can you post some pics of the amp so we can all take a look?

cheers!

**inlandbott** · 07-10-2023, 01:23 AM

Originally Posted by Doncharnin

I have owned a Mini brute for many years. I am an original owner. the serial number is 5307 I would love to know the age and fair price for it.
I am interested in selling it.
Thank you

Don

Hi, don

awesome! Can you post some pics of the amp so we can all take a look?

cheers!