Official Tono 300B amp support

[vintage_dog]

abe and docjohn: mickey commits to send you the schematics.

good news...dc heaters now installed on one of the amps. mickey and i were up until 1 am last night listening to the 300b amp with the dc heaters. well well well...the hum level went further down to only 1-3mv!! from the "normal" 10mv. we retained the hum pots which actually helped in the fine-tuned adjustments.

[Superman]

sir VD, for the existing super tono 300B owners, can we bring our amps to you for the tweaking??? how much would it cost us??? the hum noise is not audible in my listening position but it just annoys me at times when i hear it (takot din ako sa hum, hehehe! )...if it's limited, much much better for me, sir...

btw, this is OT, are the brass faceplates for the tono pre-amp already available??? thanks! god bless!

superman

[vintage_dog]

parts cost is only about p200. two options on mod: (a) you do it yourself or (b) have someone do it. if you want our technician to do it, he can do it for a fee.

i'd stick to ac heaters if hum level is below 10mv and speakers have sensitivity below 93db. but that's me.

for parts, mickey is the contact person. send him PM.

[amandarae]

Great news boss VD!

Can't wait to implement it!

Mickey, thanks in advance 'pre!

[Superman]

parts cost is only about p200. two options on mod: (a) you do it yourself or (b) have someone do it. if you want our technician to do it, he can do it for a fee.

i'd stick to ac heaters if hum level is below 10mv and speakers have sensitivity below 93db. but that's me.

for parts, mickey is the contact person. send him PM.

thanks sir VD...will get in touch with you as soon as i get back to manila...ok lang kaya kay sir Ed and his technician??? thanks, god bless!

[Doc Jr 8156]

VD,
Will the dc heaters change the performance of the amps power wise? Why would owners with <93db speakers not benefit with this mod? I can still hear the 300B hum when connected to my 91db speakers (although lesser than when connected to my single driver). Godspeed.

[arnoldc]

the DC heating *will not* affect the power output of the amp. if anybody is bothered by the hum, regardless of the sensitivity of the speakers, then by all means get the mod.

[vintage_dog]

with inputs grounded (or with volume pots at zero), a 10mv "hum" will sound much louder with say a 100db speaker versus 88db speaker. they will sound inaudible with less sensitive speakers.

with music playing, i am not bothered with any hum regardless of speaker sensitivity.

[Doc Jr 8156]

Thanks for the clarification arnoldC and VD. Godspeed.

[iceman90a]

abe and docjohn: mickey commits to send you the schematics.

good news...dc heaters now installed on one of the amps. mickey and i were up until 1 am last night listening to the 300b amp with the dc heaters. well well well...the hum level went further down to only 1-3mv!! from the "normal" 10mv. we retained the hum pots which actually helped in the fine-tuned adjustments.

I now have a modified 300b with DC heaters - galing! parang na turbo charge, better bass and PRAT

thanks to Vintage Dog, Arnoldc and Mickey!

got the new preamp faceplate too

[Doc Jr 8156]

Thanks VD. Mickey thanks for your concern. My email: revilla@usc.edu Godspeed.

[KD]

What is the input impedance of the Tono 300B?

[levi]

Hi Tonomen,

Do you still service Tono 300B that humms? Mine is getting louder that it even affects my REL subwoofer. I had mine modified by Rene but the humm is really annoying. Im willing to pay if I need to. Thanks

Levi

[TonoMan]

Levi,

First of all, have you adjusted the hum pots?

We suggest you send over to Rene since that amp has already been modified by him. VD has recently borrowed a similar Rene "upgraded" Tono 300b and it has greater hum than the stock. Other reasons for hum:

- failing tubes. i have recently tried a new set of 300b tubes (china) on them which produced greater hum

- defective transformers. i think the irons have been changed as well?

- failing bias caps

- cold solder

- rewiring or loose grounding

Rene should be able to quickly diagnose and help. We can also swap it with a quiet 110v stock export version (except tubes).

[amandarae]

Levi,

First of all, have you adjusted the hum pots?

We suggest you send over to Rene since that amp has already been modified by him. VD has recently borrowed a similar Rene "upgraded" Tono 300b and it has greater hum than the stock. Other reasons for hum:

- failing tubes. i have recently tried a new set of 300b tubes (china) on them which produced greater hum

- defective transformers. i think the irons have been changed as well?

- failing bias caps

- cold solder

- rewiring or loose grounding

Rene should be able to quickly diagnose and help. We can also swap it with a quiet 110v stock export version (except tubes).

Another suggestion, if I may. I found out that when the voltage source(wall) is about +/- 6% of the rated spec, the hum becomes louder.

Caveat: Mine is obviously a 110V version. At 110v to 115V, the hum is not as loud as at 117V(+) or 104V(-). I was able to do this by using a Variac.

Just a thought.....

[levi]

Hyperaudio was able to fix my 300B humm problem. He changed one transformer which was not upgraded during the mods. Now I can listen to music without the humm at low volume.

[nbc]

Hi guys,

I have a Tono 300B which I purchased from Rene last year.

The gold faceplate has some corrosion (pitting)... and I was wondering if I can have this fixed by you guys...???

Appreciate your help.

rgds,

nbc 0917 844 9050

[nbc]

Yoohoo... would appreciate a reply. Thanks.

[vintage_dog]

am not sure any of the guys can help you reverse the process of corrosion.

anyway, if anyone has has an idea on what to do, please let us know. i don't think there are spare faceplates since there are only a few made. you can consider re-polishing. perhaps rene can help too. good luck

[nbc]

Hi VD,

The thread title was Official Tono 300B amp support... and that's what I need... hehe.

What I want is to have the faceplate removed... the corrosion can be reversed thru application of Turco (rust remover) or some similar chemical... and then, the faceplate can be re-plated (gold or brass)... then, the Tono 300B name can be re-applied.

If I had the time to tinker with my stuff, I would do it myself... hehehe.

Would you know where the faceplates were made? Maybe I could get in touch with them.

thanks,

nbc