Folsom's great little 7297 Chip Amp

Folsom · « **Reply #760 on:** 11 Jan 2017, 09:32 pm »

It's fine to increase the value, but lowering will only reduce bass.

zek · « **Reply #761 on:** 12 Jan 2017, 11:39 am »

What is the optimum value for the input capacitor - 2uF, 3,3uF?

Folsom · « **Reply #762 on:** 12 Jan 2017, 12:05 pm »

1.5uf or larger

herby · « **Reply #763 on:** 27 Jan 2017, 02:03 pm »

Hi Folsom, I wonder where you got the idea for your TDA chip amp

Folsom · « **Reply #764 on:** 28 Jan 2017, 02:29 am »

I first tried the amp based on a DIYaudio thread, and thought it had potential.

herby · « **Reply #765 on:** 28 Jan 2017, 09:01 am »

Remember my post back in 2014 which you responded to? it was entitled byob clone and was based on using the TDA7374 chip. You weren't to favourable to it back then, what made you change your mind?

Folsom · « **Reply #766 on:** 28 Jan 2017, 10:18 am »

Don't recall any of that off hand.

herby · « **Reply #767 on:** 29 Jan 2017, 03:04 pm »

If you google altmann byob clone, its still top of the page.

Folsom · « **Reply #768 on:** 29 Jan 2017, 07:06 pm »

Ok...

I've got three board sets left over from someone who had claimed them but hasn't come through.

Folsom · « **Reply #769 on:** 31 Jan 2017, 03:32 am »

Two sets left.

Folsom · « **Reply #770 on:** 31 Jan 2017, 08:02 pm »

Yatsushiro · « **Reply #771 on:** 1 Feb 2017, 08:29 am »

Quote from: Folsom on 31 Jan 2017, 08:02 pm

One.

Folsom · « **Reply #772 on:** 2 Feb 2017, 07:09 pm »

Here's a tip for anyone using the Hammond 185 series transformer, that I was reminded of from another thread. If you didn't already check, it seems to sound best with hot wired to #6 (and consequently #2 for 115v), over #1. The only safe place to change this is at the transformer.

Tomy2Tone · « **Reply #773 on:** 8 Feb 2017, 12:35 am »

Just wanted share some pics and thoughts of the Folsom amp I picked up last Friday. I had inquired back in December if anybody had a finished amp they wanted to sell and got a response from forum member Vlad. He only had the boards for sale but with my diy skills not quite ready for something like this he was willing to build it for me. We both picked out parts we thought would be good for the build. I started out thinking just to keep it cheap and simple but it was only a matter of time before I wanted to upgrade this and that.

The case and heat sink are from diyAudio store. Transformer is an Antek AS-1215 - 100VA 15V. All wire is Neotech and the caps are Audyn True Copper. Furutech signal inputs and power inlet with Cardas gold/rhodium binding posts.

I think it came out way better than I could have imagined. Vlad really knows his stuff and did an exceptional job! I only have about 30 hours on it as of now but it really is a sweet sounding amp. I've always associated the term "musical" as being a little on the warm side with not quite enough detail. Well the word I keep thinking when trying to describe this amp is musical but in this case it has more than enough detail but also plenty of spaciousness to the soundstage. I've been finding myself just enjoying the music and not trying to nit pic what's not quite right or what could be improved upon as I really can't find much fault with it. It's definitely a foot tappin kinda amp and I really like that! Great job Folsom and great job Vlad!

Folsom · « **Reply #774 on:** 8 Feb 2017, 01:59 am »

Damn those are some barrels for input caps!

You you had it in your big system yet?

Tomy2Tone · « **Reply #775 on:** 8 Feb 2017, 02:39 am »

Quote from: Folsom on 8 Feb 2017, 01:59 am

You you had it in your big system yet?

Yes. Lately I've been using the sainsmart preamp with GE 5670 tubes as a buffer between my dac and integrated amp so for the Folsom amp it's used as preamp/volume control. I think Walkern was first to mention it here but the sainsmart and Folsom amp are a great combo. I have a Tisbury passive that I tried as well and it was good but the sainsmart just has that rich organic sound from those 5670 tubes that makes hard to not keep in there. I'm sure a better preamp would yield even better performance but for now the sainsmart is gettin it done.

lacro · « **Reply #776 on:** 8 Feb 2017, 03:47 am »

Very nice work!

All it needs now is an LED on that front panel

Odal3 · « **Reply #777 on:** 8 Feb 2017, 04:53 am »

That looks great! Enjoy!

On a related note, my shipment of parts for my second build finally came from the order I placed before xmas (was backorded)

BRN · « **Reply #778 on:** 8 Feb 2017, 05:43 pm »

Quote from: Tomy2Tone on 8 Feb 2017, 02:39 am

Yes. Lately I've been using the sainsmart preamp with GE 5670 tubes as a buffer between my dac and integrated amp so for the Folsom amp it's used as preamp/volume control. I think Walkern was first to mention it here but the sainsmart and Folsom amp are a great combo. I have a Tisbury passive that I tried as well and it was good but the sainsmart just has that rich organic sound from those 5670 tubes that makes hard to not keep in there. I'm sure a better preamp would yield even better performance but for now the sainsmart is gettin it done.

Your build looks great. It is interesting reading your comments about using Sainsmart and passive. I first used a passive with my Folsomamp and was very pleased with the results. I built a Kuartlotron buffer which worked better the Folsom and my phono preamp and DAC. Over the Christmas holiday I built a Bottlehead Quickie preamp that I was planning to use in my office. A month and a half later it is still in my main system with the Folsom amp. There is not a great difference between the Kuartlotron buffer and BH Quickie, but for my tastes I Like would the Quickie does. The additional drive and tubes add to the realism of the music ever so slightly. If I was using a tube amp I think it would be different. Both options are great and the reason I have not made a final decision on which will stay.

Folsom · « **Reply #779 on:** 9 Feb 2017, 05:29 pm »

I'm out of boards again.